Plans get lost, stuff gets bricked up, there were a number of bombs fell in that area during WWII (http://bombsight.org/?#16/51.5187/-0.1039), it can mean expensive surprises when doing building work.
When they were building the Eurostar tunnels down the road from me they found a load of disused wells that nobody had any idea existed, with unfortunate results.
I thought that ike Paris is built over its old city of tombs, London is built on top of old London. Did they forget that even though they live there?
Plans get lost, stuff gets bricked up, there were a number of bombs fell in that area during WWII (http://bombsight.org/?#16/51.5187/-0.1039), it can mean expensive surprises when doing building work.
When they were building the Eurostar tunnels down the road from me they found a load of disused wells that nobody had any idea existed, with unfortunate results.