Beijing's underground city

Built in the early 70's, at the all-time low point of Sino-Russian relationships, this underground web of tunnels and bomb shelters beneath Beijing was meant to house up to 40% of the city's population in case of Soviet attack (the rest would be evacuated to mountains outside of the city).

It's not clear how much of this 'city' sitting 10m underground and, apparently, covering more than 85sq km still remains intact given the relentless build out of high rises and the expansion of the Beijing subway system over the last 20 years - but you can still visit parts of it. We went to the only entrance officially open to the public - southwest of Tienanmen Square - but more than 90 entrances were said to have existed around the city.

The walls are covered with camouflage netting, Mao slogans, inspirational photos and useful instructions on how to put on a gas mask. Side passages led to "old persons exercise room", "children's dormitory" and "reading room". Bizarrely, after 20 minutes walk through the labyrinth we ended up in an underground silk shop complete with sales assistants ready to sell us the usual tourist trinkets. In China, nobody likes to miss an opportunity to eat or shop.