View Larger Map Cold War bunkers, abandoned Tube stations, buried rivers, deep level shelters...London's concealed features are among its most intriguing. So, in age-old Londonist tradition, we've created a map to try and show what a hollow city this is. And we need your help. We've plotted the more obvious features - the Fleet River, Zone 1 ghost stations, the Kingsway telephone exchange, etc. But we know there's a lot more down there. Please use......

In which we spend a night with some decayed, 17th century dudes, in the catacombs beneath London Bridge. Beneath the Surrey side of London Bridge, behind doors that once led to the robot-kitsch Cynthia's Bar, a new attraction is taking shape. The London Bridge Experience will open in February. Part museum, part CGI scare-fest, the LBE will take visitors on a historical tour of the 2000 year-old crossing, and down into previously disused catacombs......