Badaling

Badaling () is the site of the most visited section of the Great Wall of China, approximately northwest of Beijing's city center, in Yanqing District (within Beijing municipality). The portion of the wall running through the site was built in 1504 during the Ming Dynasty, along with a military outpost reflecting the location's strategic importance. The highest point of Badaling is Beibalou (北八樓), approximately above sea level.
Badaling Great Wall was built in the Ming Dynasty (1505) to occupy a commanding and strategic position for protecting the Juyongguan Pass (Juyongguan section of the Great Wall) to its south, further protecting the city of Beijing.
The portion of the wall at Badaling has undergone restoration, and in 1957, it was the first section of the wall to open to tourism. Now visited annually by millions, the immediate area has seen significant development, including hotels, restaurants, and a cable car. 
Transport.
Expressway.
The Badaling Expressway connects Badaling with central Beijing.
Railway.
Two China Railway lines serve Badaling:
Bus.
The 877 bus runs frequently between Deshengmen Bus Station (adjacent to the Jishuitan Station on Line 2, Beijing Subway) and Badaling.
Fame.
It was here that President Richard Nixon and his wife, accompanied by Vice Premier Li Xiannian, visited on February 24, 1972, during his historic journey to China. Many other world leaders have made a trip to the site including Margaret Thatcher, Ronald Reagan and Mikhail Gorbachev.
Badaling and the expressway were the site of the finishing circuit of the Urban Road Cycling Course in the 2008 Summer Olympics. Laps of the circuit passed through gates in the wall.
Internal traffic.
Nancheng ground cable car starts from the opposite of Zhan Tianyou Memorial Hall and goes to the fourth floor of the best viewing point of Badaling Great Wall-South.