HISTORY OF A CITY
It was rather warm even in the late autumn of 1990 when the Beijing Gardening and Greening Bureau was building apartments for its staff members outside Youanmen. A relic site emerged when a foundation was being dug about 70 metres (m) north of the Liangshui River. Construction was immediately suspended. The Beijing Cultural Relics Research Institute determined that the site was part of the city wall of the capital city of the Jin Dynasty (1115–1234).
The formal archaeological excavation work was carried out about 45 m south of the original construction base across a 35-m-wide area. The topsoil was removed. Excavation went about two m deep. It was carried out layer by layer with six detectors, with an excavated area of 660 square metres (sq.m). The grand features of the Jin capital aquatic facility finally met the world. About 800 years ago, the facility was constructed across the city wall. It was made of wood, stone, iron, sandstone and other materials. As many as 1,800 spikes over one m long, 530 cubic metres (cu.m) of prefabricated stone structures and over 2,500 silver ingots were used in its construction. Water flowed through a water culvert made from wood and rock, passed through the city from north to south and flowed into a moat. The unique museum features the underground relic site and historical displays. The relic site provides valuable material that is useful for studying the Jin capital and ancient Chinese cities.
Capital of the Jin Dynasty
After Wanyan Liang became Emperor Hailing of the Jin Dynasty in 1115, he proclaimed that the capital would be moved from Shangjing to Yanjing, which is now Beijing. Wanyanliang appointed Zhang Hao to commission the construction of the new capital, which was modeled after Bianjing, capital of the Northern Song Dynasty (AD 960–1127) in planning and architectural style. The city's area was expanded in the east, south and west directions. Over 1.2 million people toiled more than 700 days and nights to complete the project. In 1153, the capital was moved to Yanjing, which was renamed Zhongdu at the time.
Zhongdu (Middle Capital) becoming the capital was the start of Beijing's status as the capital of China. Beijing now has a history of more than 860 years as the capital. During the most prosperous period of the Jin Dynasty, its territory reached as far north as the outer Xing'anling Mountains, east as the Okhotsk Sea and the Japan Sea, southeast as Korea and west as what is now the northwest part of Shaanxi Province. However, in 1215, the capital fell to the Mongolian army, and the city was completely destroyed. The rulers of the Jin Dynasty moved the capital to Luoyang, and Zhongdu was no more. A variety of items have been uncovered from the aquatic relic site of the Jin Dynasty, including small porcelain dog figures for children, incomplete sets of chess pieces, bronze mirrors with handles and patterns of sea dragons, broken porcelain bowls, Cizhou kiln porcelain bowls and even explosives.
Building of a Waterway
Water is the lifeblood of a city. A water gate is important infrastructure. It lets river water in and out under the city wall. Some people say that the reason it is called a water gate is because people in ancient times used to guard the wall like they were guarding a garrison to prevent enemies invading through the water courses.
The relic site of the facility is rectangular, and the long sides run from north to south. It is 5.6 m below the surface, 43.4 m from north to south and 7.7 m wide at the centre. The inlet and outlet are trumpet-shaped and have a width of 12 m. The structure includes the stone pavement of the water culvert and the residual stone walls on both sides. The facility is a wood-and-stone structure commonly used in ancient buildings with a wooden foundation made from over 1,800 pieces of cedar wood, each measuring 15 centimetres (cm) in diameter and one to two m in length, inserted densely into the ground vertically. The part above the ground was carved into a tenon-shaped structure to accommodate large, squareshaped crossbars. Stone slates were put on top of the wood for water to flow through. The tenon structure connects the wooden crossbars with the underlying wood. The crossbars are interconnected by silver ingot tenons. The crossbars are stabilised with stone slates held in place by iron nails and cedar spikes. The underlying timber pile, wooden crossbars and stone slabs are closely connected to each other to form a unified structure.
The water gate is set under the gate of the city wall to allow pond water and rainwater to flow through to join the Liangshui River. This water gate is also the exit of the Jinshui River in the capital. The two rivers meet at the gate.
Establishment of a Museum
This water gate is the only water gate that can be found in the capital with a complex structure. Its scientific design, solid structure and magnificent scale make it rather rare. It establishes the location where river flowed out of the capital city of Jinzhong and provides a reliable physical evidence for studying the architectural style and water system of the past capital.
The People's Government of Beijing Municipality established the Liao and Jin City Wall Museum at the site. It opened in April 1995. The museum is a municipallevel cultural relics protection site. In June 2001, it was designated as a national key cultural relics protection site. The museum was built on the site of the Jin Dynasty capital water gate and occupies 2,500 sq.m of floor space. There are two floors above ground and one underground. It has permanent and temporary exhibitions in the above-ground halls. The ancient water gate structure is preserved in the underground space.