Mystery Building Posted byOllie 7 March 2008 2 Comments on Mystery Building Tweet Here’s a mystery building for you – can you guess what it is? It’s in the City of London. Tweet Related Posts Name That BuildingHere's a building - actually two, the main one is on the left - as seen on an orienteering map. Dark grey = building, Light grey = canopy. Hint 1:… b27 b28Photograph by Bossanostra.