I was walking in the Fleet Street area the other day and suddenly spotted a series of stickers on the footpath that spoke about the lost river Fleet. My curiosity aroused, I tried following the trail but lost it after a point. I came home and tried to see if I could dig up any more about it. I found this Guardian article about how the Environment Agency is indeed resurrecting, so to speak, the lost rivers of London, and this map. And then finally this Wikipedia article that says that in January of this year, the River Restoration Centre was set up as a partnership between the Environment Agency, Natural England and the Greater London Authority as part of a plan to reinstate underground rivers of the city by the office of the Mayor of London. Nice one, Boris.