TEMPLE OF HEAVEN
Temple of Heaven (within the Temple of Heaven Park four kilometers south of Tiananmen Square) is a complex of Taoist buildings situated in southeastern Beijing. Literally the Altar of Heaven, it was visited annually by the Emperors of the Ming and Qing dynasties (1368-1911), who prayed to Heaven for good harvests.
The Temple of Heaven complex covers an area of 270 hectares, about three times the size of the Forbidden City. The main buildings in the park were built in 1420 during the Ming Dynasty (1368–1644) by Emperor Yongle for worshipping the heaven and the earth. The complex was extended during the reign of Emperor Jiajing in the 16th century and was renovated in the 18th century by Emperor Qianlong. The temple has been described as "the noblest example of religious architecture in the whole of China." The buildings found here were built at the same time as the Imperial Palace, and they are noted for their exquisite architecture and harmonious placement within the park among rows of cypress trees, some of which are said to be 800 years old.
The Temple of Heaven was designed to mark the meeting point between heaven and earth. Known to Chinese as Tiantan, it was expanded and reconstructed during the reigns of the Emperor Jiajing and Emperor Qianlong. Built to offer sacrifice to Heaven, the Temple of Heaven is enclosed with a long wall. The northern part within the wall is semicircular, symbolizing the heavens and the southern part is square symbolizing the earth. The northern part is higher than the southern part. This design shows that the heaven is high and the earth is low and the design reflected an ancient Chinese thought of ‘The heaven is round and the earth is square’. It is regarded as a Taoist temple, although Chinese Heaven worship, especially by the reigning monarch of the day, actually predates Taoism.
If all of its elements are included, the Temple of Heaven has an area of about 2.7 square kilometers. It is the largest temple complex in China and one the largest in the world but most of it is garden and open area. The temple’s building are located in different places according to the temple’s cosmology. It was the place where emperors of the Ming and Qing Dynasties would pray to heaven for good harvests. It was one of the most strictly protected and preserved cultural heritages of China. Today, about 12 million people visit the temple every year.
Temple of Heaven: an Imperial Sacrificial Altar in Beijing was designated a UNESCO World Heritage Site in 1998. According to UNESCO: “The Temple of Heaven, founded in the first half of the 15th century, is a dignified complex of fine cult buildings set in gardens and surrounded by historic pine woods. In its overall layout and that of its individual buildings, it symbolizes the relationship between earth and heaven – the human world and God's world – which stands at the heart of Chinese cosmogony, and also the special role played by the emperors within that relationship. [Source: UNESCO]
The site is important because: “1) The Temple of Heaven is a masterpiece of architecture and landscape design which simply and graphically illustrates a cosmogony of great importance for the evolution of one of the world’s great civilizations. 2) The symbolic layout and design of the Temple of Heaven had a profound influence on architecture and planning in the Far East over many centuries. 3) For more than two thousand years China was ruled by a series of feudal dynasties, the legitimacy of which is symbolized by the design and layout of the Temple of Heaven.
Location: No.1,Tiantan Road,Dongcheng District, Tel: +86 10 6702 8866; Admission: 15 yuan (US$2.36) per person (summer); 10 yuan (US$1.58) per person (winter) Websites: Official Temple of Heaven Park site tiantanpark.com; Wikipedia article wikipedia.org ; UNESCO World Heritage Site: unesco.org
Altar of Heaven
Altar of Heaven (within the Temple of Heaven) was the altar used for conducting the Worshiping of Heaven Ceremony held on the winter solstice. Constructed it 1530, it was regarded as the center of he earth and consists of three marble tiers, representing (from the top down): heaven, earth and man. The altar was originally covered deep blue glazed slabs and then with green stone slabs surrounded by white marble balustrades when t was enlarged in 1749. The balustrades, slabs in each tier and the steps in each flight of stairs are arranged in multiples of the number 9, symboling the 9 layers of heaven.
According to UNESCO: Located south of the Forbidden City on the east side of Yongnei Dajie, the original Altar of Heaven and Earth was completed together with the Forbidden City in 1420, the eighteenth year of the reign of the Ming Emperor Yongle. In the ninth year of the reign of Emperor Jiajing (1530) the decision was taken to offer separate sacrifices to heaven and earth, and so the Circular Mound Altar was built to the south of the main hall for sacrifices particularly to heaven. The Altar of Heaven and Earth was thereby renamed the Temple of Heaven in the thirteenth year of the reign of Emperor Jiajing (1534). The current arrangement of the Temple of Heaven complex covering 273ha was formed by 1749 after reconstruction by the Qing emperors Qianlong and Guangxu. [Source: UNESCO]
Millennium Altar is a futuristic structure raised under Jiang Zemin as a modern answer to the Temple of Heaven and Earth Altar.
Temple of Heaven Park
Temple of Heaven Park is one of the most visited and largest parks in Beijing. Covering 275 hectares (675 acres), it is a fun place to go especially on Saturday or Sunday morning to watch Chinese enjoy a day outside. In one area old men gather with their songbirds in exquisite cages. In another couples practice their ballroom dancing moves. Throughout the park you can groups and individuals doing tai chi and wu shu with swords, parents playing badminton with their children, children flying kites, elderly people doing Mao-era group dances and singing revolutionary songs, and people of all ages playing Chinese versions of lawn darts and dodge ball.
The gates to the Temple of Heaven Park open at 6:00am. At that time there is already surprising number of people engaged in some activity: line dancers, tai chi practitioners, kite flyers, people kicking a large shuttle cock (ti jian zi) in a circle, people walking backwards, people scratching their backs against trees, and people vigorously rubbing their heads and walking on their toes and hands, and hanging from trees by their feet.
Many people play a Chinese version of paddle ball that combines tennis with tai chi. Players toss a ball and strike it with smooth fluid motions rather than abrupt swats and twirl around while they do this as if they were dancing. There are basketball or tennis courts, but not many joggers. Bike have to be parked outside.
Temple of Heaven Ceremony
Temple of Heaven Ceremony: The Temple of Heaven is where the Ming and Qing Emperors worshiped to heaven and prayed for bumper crops. Each year, on the winter solstice, the Emperor offered a sacrifice to bring good fortune in the coming year and maintain harmony with heaven. It was the most important event on the emperor's calendar. In the spring the Emperor presided over a harvest ceremony, intended to ensure good harvests in the following autumn. Each ceremony was held at its own altar at the Temple of Heaven.
Before the Worshiping Heaven Ceremony on the winter solstice the Emperor entered the Hall of Abstinence at the Imperial Palace in the Forbidden City to pray and fast. For three days the Emperor could not eat meat or drink wine, have contact with women, make merry and take care of legal matters. After that he spent some time in the Imperial Vault, ritually communicating with the gods before spending the night in the Hall of Prayer for Good Harvest
On the day of the ceremony the Emperor traveled with an entourage that included elephant chariots, flagbearers, horse chariots, noblemen, musicians and acrobats to the altar where the ceremony was held. In a ceremony that was closed to the public the emperor chanted prayers and presided over sacrifice of animals on sacred tablets on a round Altar of Heaven.
Hall of Prayer for Good Harvests
Orientation of the Temple of Heaven
Orientation of the Temple of Heaven: The northern parts of the outer surrounding walls of temple are semicircular, representing the heavens, while the southern parts are square, representing the earth. A double wall separates the temple into two parts — the inner temple and outer temple, with the main structures being in the inner one. The whole area covers 273 acres.
The inner temples is further divided by a wall into two groups. The north structure embraces the Altar of Praying for Good Harvests within the Hall of Prayer for Good Harvests, the principal buildings used to pray in the spring for fertility and abundant harvests. The south area features the Altar of Heaven was used to worship heaven on the winter solstice. It is made up primarily of a round marble terrace called the Circular Mound. The two altars are connected by a 360-meter-long raised walk called the Red Step Bridge, which is arranged in line with a 1,200-meter-long north-south axis flanked by century-old cypress trees.
Near the West Celestial Gate of the south part of the Inner Temple is the Abstinence Hall, where the Emperor fasted before the rituals. A short distance away through the western gate in the outer temple is the Divine Music Office, where teaching and performances of ritual music was carried out. Other important buildings include the Hall of Heavenly Emperor, the Imperial Vault of Heaven, the Beamless Hall, the Long Corridor, and the Longevity Pavilion.
According to UNESCO: The Temple of Heaven is an axial arrangement of Circular Mound Altar to the south open to the sky with the conically roofed Imperial Vault of Heaven immediately to its north. This is linked by a raised sacred way to the circular, three-tiered, conically roofed Hall of Prayer for Good Harvests further to the north. Here at these places the emperors of the Ming and Qing dynasties as interlocutors between humankind and the celestial realm offered sacrifice to heaven and prayed for bumper harvests. To the west is the Hall of Abstinence where the emperor fasted after making sacrifice. The whole is surrounded by a double-walled, pine-treed enclosure. Between the inner and outer walls to the west are the Divine Music Administration hall and the building that was the Stables for Sacrificial Animals. Within the complex there are a total of 92 ancient buildings with 600 rooms. It is the most complete existing imperial sacrificial building complex in China and the world's largest existing building complex for offering sacrifice to heaven. [Source: UNESCO]
The siting, planning, and architectural design of the Temple of Heaven as well as the sacrificial ceremony and associated music were based on ancient tenets relating numbers and spatial organisation to beliefs about heaven and its relationship to people on earth, mediated by the emperor as the ‘Son of Heaven’. Other dynasties built altars for the worship of heaven but the Temple of Heaven in Beijing is a masterpiece of ancient Chinese culture and is the most representative work of numerous sacrificial buildings in China.
Buildings in Temple of Heaven
The temple is comprised of several buildings and walls with numerous gates. Each piece of architecture has symbolic meaning. The four central columns, for example, represent the four seasons. The square ends represent the earth, and the semicircles, the heavens. The main buildings of the Temple lie at the south and north ends of the inner part. The most notable buildings are The Circular Mound Altar; the Imperial Vault of Heaven and the Hall of Prayer for Good Harvest. Also, there are some additional buildings like Three Echo Stones and Echo Wall. Almost all of the buildings are connected by a wide bridge called the Vermilion Steps Bridge. Among the interesting sights in the park are the Imperial Vault of Heaven with a gilded cupola and the three-tiered Circular Altar. The imperial north-south axis runs from the Temple of Heaven to the Forbidden City to the main Olympic site.
Palace of Abstinence
Palace of Abstinence (within the Temple of Heaven) is where the Emperor went to pray and fast before conducting the ceremony for the good harvest on the winter solstice in the Temple of Heaven. For three days the Emperor could not eat meat or drink wine, have contact with women, make merry and take care of legal matters. There is a hall that serves the same purpose at Imperial Palace in the Forbidden City.
The Palace of Abstinence was built on 1420 and covers an area of 40,000 square meters. Located to the southwest of the Altar of Prayer for Grains, it is square in shape and covered with green tiles, symbolizing the Emperor’s obedience to heaven. Among the rooms inside are the Beamless Hall, the bed chambers, a belfry and a stone pavilion housing a bronze statue representing justice and righteousness and rooms for guards, servants and eunuchs. The palace is surrounded by a double wall and double moat.
Echo WallEcho Wall (within the Temple of Heaven) is the circular surrounding wall of the Celestial Warehouse. The hard smooth wall is shaped so that it reflects sound waves. If you stand at the center of the alter near three large stones and shout, a very loud echo will occur. If two people stand by the wall behind the East Annex Hall and the West Annex Hall and speak facing the north they can hear each other clearly. The effect is best achieved when the area is not crowded and there is not a lot of background noise.
Hall of Prayer for Good Harvests
Hall of Prayer for Good Harvests (within the Temple of Heaven) is the most famous and recognizable building in the Temple of Heaven. Built in 1420 and rebuilt in 1545 and 1751, it is 38.2 meters-high and 24.2 meters in diameter and boasts three gently-sloped, blue-glazed-tiled roofs topped by a golden ball. The entire building is made completely of wood (no nails or metal braces were used) and is supported by immense pillars, symbolizing the four seasons, the 12 months of the year, the 12 divisions of the day and night and all the constellations. Make sure to look up and admire the lavishly decorated ceiling.
The hall is a good illustration of how Chinese numerology works and takes advantage of good luck numbers like the number 3 and 9. It has three stories, representing from top to bottom: the heavens, earth and humankind. The top level has nine rings, each composed of nine stones, for a total of 81 stones. The middle level has 10 through 18 rings, each with nine stones. The bottom level has 19 to 27 rings, each with nine stones, with final and largest ring having 243 stones (9x9x9). The stairs and balustrades are also organized in multiples of nine. Some regard the Hall of Prayer for Good Harvest as the most beautiful structure in all of China. The original hall was called the Great Hall for Sacrificial Rituals. It was rectangular in shape and was used to worship both the heaven and the earth. The hall rebuilt in 1545 was known as the Great Hall for Offering Sacrifices. It featured a triple-eaved roof of glazed tiles, with each roof being a different color: blue, yellow, and green, representing the heaven, earth and mortal world, respectively. The hall took its present shape when it was rebuilt in 1751. The three roofs were made with azure tiles only and topped by the gilded sphere. It was designated the Hall of Prayer for Good Harvest and was used exclusively to pray for good harvest in the early spring.
Imperial Vault of Heaven
Imperial Vault of Heaven (within the Temple of Heaven) is where the treasures and tablets used in the Worshiping Heaven Ceremony were stored. Built in 1430 ad rebuilt into its current shape in 1752, it is an octagonal tower, made completely of wood and, measuring 19.5 meters-high and 15.6 meters in diameter and has blue tiled roof topped by a gilded sphere. The Imperial Vault of Heaven is a finely interlaced wooden structure with a bluish-green coffered ceiling with a gilded dragon playing with a pear at the center. The Long Corridor, whose 72 rooms stored sacrificial offerings, is now a theater. Singers sing revolutionary songs to the wining melody of an ehru and rhythm from wooden clappers.
Central Axis of Beijing
The Central Axis of Beijing (including Beihai) was nominated to be a UNESCO World Heritage site in 2013. Important elements include: Yongding Gate, Temple of Heaven, Temple of Agriculture, Tian'anmen Square complex, Imperial Ancestral Temple, Altar of the Land and Grain, the Forbidden City, Jingshan Hill, Bell Tower, Drum Tower, Nanluoguxiang, Yandai Bystreet historic area, and the Beihai water system.”
According to a report submitted to UNESCO: “The old city of Beijing was first built in the Yuan Dynasty (mid-13th Century, formerly known as "Dadu"), and further developed and perfected in the Ming and Qing Dynasties (early 14th Century to early 20th Century). With eight hundred years’ history of urban development, it is now the largest imperial capital city still existing in China and a classic model of ancient Chinese urban planning. As an outstanding example of feudal China’s capital, the old city of Beijing enjoys a prominent position in the world history of urban planning and development. [Source: National Commission of the People's Republic of China for UNESCO]
“The Central Axis is the best preserved core area of the old city of Beijing. The Central Axis of Beijing is 7.8 kilometers long starting in the south of the city from the Yongding Gate, running across the Zhengyang Gate, Tian'anmen Square, the Forbidden City, the Jingshan Hill, and ending with the Drum Tower and Bell Tower in the north. Most of the essential buildings in the old city of Beijing are constructed along the axis. The Central Axis ingeniously organizes the imperial palaces, the imperial city, temples and altars, markets, streets from feudal times and the Tian’anmen square complex built after the founding of the People’s Republic of China in 1949. As the most representative and important section of the old city of Beijing, it is the core of old Beijing’s spatial pattern and demonstrates the magnificent spatial order of the urban space.
“As the core of old Beijing city, the Central Axis of Beijing demonstrates the ingenious urban planning in the Yuan, Ming and Qing dynasties, as well as the People's Republic of China. Its location and design not only represent the “value of the center” in traditional Chinese culture, but also highlight Chinese philosophy's respect to the nature and its appreciation of mutual existence between man and nature. Following the urban planning principles for capital cities recorded in Zhouli — Kaogongji (Rites of Zhou: Records of Construction), the Central Axis of Beijing is the physical carrier of the ancient Chinese ritual system, emphasizes well-organized social orders and stands as a creative practice and typical example of traditional Chinese social governance applied to urban planning.
"The Central Axis of Beijing" witnesses the major changes in Chinese society and values in the last eight centuries. Dadu City of the Yuan Dynasty set a model to control urban development and linked up important public buildings through the central axis. In the Ming and Qing dynasties, a number of halls and palaces, royal gardens, altars and temples were added to build up the Central Axis as the center and symbol of Beijing city and enriched its cultural context. Chinese governments since the Republic of China carried out renovations in the area around the Front Gate and Tian'anmen Square in order to adapt to modernization and new ideology. As a result, the spatially isolated area has been set free and vitalized, while the symmetrical pattern was observed. Although some historic remains along it have been altered or vanished due to renovations in modern and contemporary times, the Axis as one entity adapts to the social needs in different periods and plays an important role in the development of Beijing city. The "Central Axis of Beijing" also reflects the evolution and accumulation of the historic urban landscape during the last eight centuries.
History of the Central Axis of Beijing
According to a report submitted to UNESCO: “"The Central Axis of Beijing" has its root dated back to the planning and design of the Dadu City in the Yuan Dynasty. The Yuan Dynasty initially determined the location of the Central Axis based on the water system with imperial grain transport capacity (today’s Six Lakes). Along with the natural conditions, the Central Axis was designed and constructed to realize the ideal city plan in traditional Chinese culture. The Ming Dynasty built the Forbidden City on the basis of the Yuan palaces, and erected the symbolic Jingshan Hill in the north, and the new Bell Tower and Drum Tower, Imperial Ancestral Temple, and Altar of the Land and Grain. As the outer city expanded and the new Temple of Heaven and Temple of Agriculture built on both sides, the Central Axis extended further to Yongding Gate in the south, marking the completion of the Central Axis system. The overall layout of Beijing city remained intact throughout the Qing Dynasty. The Central Axis has undergone functional renovation and spatial re-organization during the Republic of China and People's Republic of China. In particular, the renovation and expansion of Tian'anmen Square shifted the spatial and symbolic focus of the Central Axis from the Forbidden City to Tian'anmen Square in the south.” [Source: National Commission of the People's Republic of China for UNESCO]
“Over centuries of urban evolution, some architectures along the Central Axis of Beijing underwent demolition or reconstruction (for example, the Yongding Gate and Di’an Gate), and the spatial pattern has been partially altered (for example, Tian’anmen Square). However, the Central Axis as a whole has always been the major axis and the fundamental basis of Beijing’s urban planning and enjoys full respect. Partial changes have generally been associated with important historical events and reflect the social development and value systems in specific periods of time. Reconstruction of vital components for the integrity(for example, the Yongding Gate) were undertaken strictly pursuant to historical documents, pictures and surveying drawings by using traditional materials and techniques.
“During centuries’ evolution, changes of political regimes as well as social, economic and urban development influenced the architectures and spatial pattern of the Central Axis. However, as the most essential feature and the basis of urban planning, the Central Axis has been given full respect in historical periods and exhibits the capacity of inclusiveness of the ingeniously designed spatial order for social changes, demonstrated by its own evolution. Today, "the Central Axis of Beijing" is not only a representative physical carrier of recalling the traditional urban life, but an urban landscape still in full vigor. [Source: National Commission of the People's Republic of China for UNESCO]
“In the context of history, spatial structure and cultural significance, "the Central Axis of Beijing", stretching 7.8 kilometers from Yongding Gate in the south to the Bell Tower in the north, can be divided into the following urban landscape areas: the place of worship in the Outer City between Yongding Gate and Zhengyang Gate; the area from Zhengyang Gate to Tian'anmen Square; the "Halls and Palaces" from Forbidden City to Jingshan Hill; the "Market" area around the Drum Tower and Bell Tower; and the "Six Lakes" water area. These areas make up a full picture scroll of "the Central Axis of Beijing" and reflect the evolution and accumulation of the historic urban landscape.”
Design of the Central Axis of Beijing
According to a report submitted to UNESCO: “The Central Axis of Beijing was constructed with careful urban planning and design and went through constant evolution of almost eight centuries. Organized according to specific design principles, it is a uniform spatial entity centering historical remains including imperial palaces, imperial gardens, modern and contemporary public architectures and city square and is composed of imperial temples and altars, residential houses and neighborhoods, landscape gardens, historic streets, hydraulic projects, defensive systems as well as important symbolic architectures and urban landscapes. As the core of the spatially symmetrical old Beijing city, the Central Axis and surrounding areas form a masterpiece of ancient and contemporary urban planning. Its planning and evolution reveal how the Chinese people applied science, aesthetics and ancient philosophy into the design of a capital city, and how they established social order and regulated social life through urban planning. The Central Axis of Beijing demonstrates great ingenuity of human in urban planning. [Source: National Commission of the People's Republic of China for UNESCO]
“The Central Axis of Beijing and surrounding areas witness an orderly distribution of important architectures such as the palaces, governmental offices, temples and altars, mansions, residential houses and city gates that constitute a rich and magnificent spatial order with profound symbolism. The spatial order, architecture form and their colors are arranged in an orderly and uniform manner yet present great diversity to provide special evidences for the Chinese ritual system, imperial culture, folk customs and fengshui. The Central Axis not only witnessed the already vanished social life of ancient China, but also functions as living carrier of the ever-lasting traditional Chinese culture and value system.
“Traditional Chinese urban planning, especially the capital planning, is mainly influenced by three ideologies. One is “observing heaven and earth” to express Chinese traditional theories of “harmony between man and nature” and the “divine rights of emperors”; the second is the so-called “ritual system” in “Zhouli — Kaogongji” to plan city according to the ranks of governors in the city; the third is the principle put forward by Guanzi to rationally plan cities in accordance with natural environment and urban population.
“Beijing, as the location of the capital, is exactly under the Polaris, where the imperial palace is strictly under the Heavenly Palace in the myths. This reflects the “observing heaven and earth”; the pattern of courts in the front and markets behind, ancestral shrines on the left and altar of land and grain on the right along the central axis shows the traditional ritual system and the influence of “Zhouli — Kaogongji”; the identification of Beijing’s central axis, and the spatial relation between the central axis and the Six Lakes water system, Yongding River and Chaobai River reflect the rationality and the planning principle of “harmony with natural environment” in “Guanzi”.
“When compared with historic capital cities Xi'an, Luoyang, Kaifeng, and Nanjing built earlier than Beijing, only old Beijing city remains its overall pattern and central axis that exhibits the ritual system emphasizing “the value of the center”. When compared with historic capital cities Xanadu and Zhongdu of the Yuan Dynasty built approximately at the same time with Beijing, Beijing has the largest axis system that cost the longest time to form, is of the most significance in ancient Chinese urban planning. Therefore the Central Axis of Beijing has more outstanding values than those of other historic capital cities of China.”
Philosophy and Ritual Purposes of the Central Axis of Beijing
According to a report submitted to UNESCO: “The Central Axis of Beijing explains the traditional Chinese philosophy of the relation between man, city, heaven and nature, and is a typical and well preserved epitome of the thousand years’ development of Chinese capital planning. It represents the summit of capital design and construction in the Ming and Qing dynasties and is an outstanding example of urban planning in the oriental civilization. [Source: National Commission of the People's Republic of China for UNESCO]
“When the Mongols started the Yuan Dynasty and conquered the entire China, the Yuan emperors could view China's geography from a wider perspective. Combined with the viewpoint of Neo-Confucianism master Zhu Xi in the Southern Song Dynasty that “Hebei’s capital (Beijing) is exactly at the center of heaven and earth”, Beijing was regarded as the center of the world at that time. Beijing's central axis was not only the axis of the capital city, but a central line to control the whole country. It linked up Yanshan Mountains, the Yellow River, Mount Taishan, Huai River, Huainan mountains, the Yangtze River, and Jiangnan mountains with the Central Axis of Beijing as its core.
“The central axis of the country and the city as well as natural conditions and traditional ritual system were integrated into the urban planning and development of Beijing, making Beijing the best model combining the Neo- Confucianism since the Song Dynasty and the ideal city planning in Zhouli — Kaogongji. Such a design exhibits distinctive cultural value, the essence of traditional Chinese philosophy and the interpretation of Chinese tradition that pays widespread attention to the relationship between man and nature, urban construction and natural environment throughout human history.”
Image Sources: Province maps from the Nolls China Web site. Photographs of places from 1) CNTO (China National Tourist Organization; 2) Nolls China Web site; 3) Perrochon photo site; 4) Beifan.com; 5) tourist and government offices linked with the place shown; 6) Mongabey.com; 7) University of Washington, Purdue University, Ohio State University; 8) UNESCO; 9) Wikipedia; 10) Julie Chao photo site.
Text Sources: CNTO (China National Tourist Organization), UNESCO, Rough Guide for Beijing, Lonely Planet guides, New York Times, Washington Post, Los Angeles Times, National Geographic, The New Yorker, Time, Newsweek, Reuters, Associated Press, AFP, Compton's Encyclopedia and various books and other publications.
Updated in May 2020