Mao Zedong's secret subterranean city / by Thomas O'Malley

This ranks as one of the coolest assignments an editor has ever given me.

"So, there's this English guy in Beijing, he's the one who knows how to get down into the old nuclear bomb shelters under the city. Can you find him and have a look?"

Hell yeah. What was unexpected - and a bit sad, in a way - is that I might be the last person to access this or any remaining part of Mao Zedong's secret underground city, dug at the height of cold war paranoia with Russia in the 70s. Workers were bricking up the access tunnels as we made our way down through the damp concrete corridors. With the large-scale redevelopment of Beijing, these (admittedly rather shallow) shelters and tunnels are rapidly disappearing, as modern buildings demand ever-deeper foundations.

The article was for CNNGo to support a Beijing city special on the news channel at the time. Actually, up until about 2007 there was a sort of semi-official underground city 'museum' you could visit some way south of Tiananmen Square, with schools, a theatre, dormitories etc. I sought it out in early 2008, and found a doorway with this sign pinned to it. As far as I know it never opened again.