Wikipedia says a Tallboy hit it, but IIRC, it was an earlier raid that knocked the chunk off the top and a later Tallboy missed, but the seismic shockwave moved the LOX tank off its mount and that's when they decided to abandon it.

The other preserved V-bomb site in northern France is an even better visit. That of the huge concrete dome roofed facilty at Wizernes, which was also successfully attacked with Talboys.

http://www.v2rocket.com/start/deployment/wizernes.html

Mimoyecques(sp?)
 

This site was where the forerunner of the Iraqi 'supergun' (the V3) was built during WW2. This also received the attention of Tallboys and Grand Slams, and is well worth a visit. Not that far from Calais, IIRC.
BTW, the U-Boat bunker 'Valentin' is indeed very big - if I can remember how to post them, I will post some pics on here later. Half of it is abandoned, whilst the other half is still in use by the Bundesmarine for storage.

This was the "V3" site in Northern France. Amazingly a Tallboy hit and went down the shaft of one of the guns and detonated at its base. This caused a huge secondary explosion, killing hundreds of slave workers and wrecking the facility.