Underground City, Cold War bunker in Beijing, China

The Underground City is a Cold War bomb shelter of tunnels beneath central Beijing, dug 8 to 18 metres down and covering 85 square kilometres. Its passages have concrete walls and thick concrete main gates, with 2,300 ventilation shafts that can be sealed against poison gas and radioactive fallout. Visitors once entered through a small shop front at 62 West Damochang Street in Qianmen.

Construction began in 1969 when tensions between China and the Soviet Union ran high, lasting roughly a decade to complete. This vast network was built as protection against potential military threats to the city.

The tunnels carry the slogans painted during the digging, such as "Accumulate Grain" and "For the People: Prepare for War, Prepare for Famine", beside murals of volunteers at work and a portrait of Mao Zedong. Chambers are still labelled with their planned functions, from cinemas and hospitals to arsenals. From 1980 the spaces were turned to peacetime use as cheap hotels, shops and workshops.

The site is not open to visitors today, having been closed to the public in 2008 and remaining inaccessible for tours. You can learn about its history through museums and documentary sources instead.

The tunnels were dug by more than 300,000 local volunteers, including school students, and some stretches were excavated without heavy machinery. Materials came partly from dismantling centuries-old city walls and gates, among them Xizhimen, Fuchengmen and Chongwenmen.