Tan Zhe Si, or Deep Pond and Zhe-Tree Temple in English, located near Beijing's Western Hills, is the Beijing area's oldest Buddhist temple. In fact, some believe that the temple actually predates the city, i.e., that it was left standing when the Mongol hordes of Genghis Khan, in CE 1215, razed the Jin (CE 1115-1234) Dynasty capital, Zhongdu, where Dadu cum Beijing was later to be built, to the ground.
The temple's name derives from the fact that behind the temple lies a deep pond, called the Dragon Pond, and in front of the temple grow a number of Zhe trees (Cudrania tricuspidata), or wild mulberry trees. According to official though scant documentation, Tanzhe Temple was originally build during the Jin Dynasty, though, as if to undermine this, it seems that the two "Emperor trees" (the "Emperor" and the "Empress", the two ginko trees mentioned below) standing nearby the Hall of Three Sages were planted slightly earlier, during the Liao (CE 916-1125) Dynasty.
However, most of the temple's current buildings stem from the Ming (CE 1368-1644) and Qing (CE 1644-1911) Dynasties, though the temple has retained many of its older elements. For example, some of the temple's pagodas stem from the original Jin Dynasty construction period, while others stem from the Yuan (CE 1279-1368), Ming, and Qing Dynasties. The pagodas contain the ashen remains of the monks - and nuns - who spent their lives at this monastery, which explains the large number of pagodas.
The central part is characterized by splendid structures like archways, mountain gates, altars and Buddhist Halls. Bilu Pavilion is the highest structure in the central temple, in front of which are many rare bushes, such as the calyx canthus - or fragrant winter tree, aka wintersweet (Chimonanthus fragrans) in the UK - and the purple yulan, a moderately tall (up to 10 meters) decidious tree in the magnolia family (Magnolia heptapeta), with the characteristic cup-shaped, fragrant white flowers of a magnolia tree, and with purplish bark. When the yulan blossoms early in spring, people flock to the temple to see, and smell, its pretty, fragrant blossoms. A 200-year old purple yulan growing on the temple grounds is considered to be the largest such tree in northern China.
Among the temple's other trees, two tall ginkgo trees - another decidious tree native to China, though not in the magnolia family (genus Ginkgo biloba, its fleshy, yellowish seeds have a disagreeable odor) - planted during the Liao Dynasty and always referred to as "The Emperor" and "The Empress", were rechristened by Emperor Qianlong of the Qing Dynasty as "The King of Trees" and "The Emperor's Wife", respectively.
The eastern part of the temple contains a number of rooms with smaller courtyards. The abbot's room is here, as well as the rooms that were used by successive emperors whenever they stayed here. These rooms have been restored to their original austere atmosphere.
The western part is noted for its solemn and imposing architectural styles, such as Youjie Altar and Guanyin Hall, the Goddess of Mercy and the "patron saint" of seafarers. Guanyin Hall is associated with Princess Miaoyan, the daughter of Kublai Khan, grandson of Genghis Khan and the first emperor of the Yuan Dynasty, who ruled China from 1260 to 1294. According to the story of Princess Miaoyan's presence at Tanzhe Temple, the princess felt such guilt over the many lives taken in battle during her father's reign that she converted to Buddhism and entered the monastery in order to do penance in her father's name. It is also said that the princess is buried somewhere on the temple grounds, though this remains more rumor than fact. The pagoda that presumably contains the earthly remains of Princess Miaoyan is a solid brick, five-storey structure.
Tanzhe Temple, like most Buddhist temples in China, is an active place of worship and study. Monks regularly perform religious ceremonies here.