The city's history dates back three millennia. As the last of the Four Great Ancient Capitals of China, Beijing has been the political center of the country for much of the past eight centuries. The city is renowned for its opulent palaces, temples, gardens, tombs, walls and gates, and its art treasures and universities have made it a center of culture and art in China.
The Beijing city wall was a series of fortifications built between 1436 and 1553. The Inner city wall was 24 km long 20 metres thick at ground level and 12 metres thick at the top. The wall was 15 metres high, and it had nine gates. This wall stood for nearly 530 years, but in 1965 it was removed to allow construction of the 2nd Ring Road and the Line 2, Beijing Subway. Only one part of the wall is extant, in the southeast, just south of Beijing Railway Station. The Outer city walls had a perimeter of approximately 28 kilometres. The entire enclosure of the Inner and Outer cities formed a "凸" shape with a perimeter of nearly 60 kilometres.