I took this one in In my visit to Dover. It is an abandoned search light battery used in World War Two, situated in Langdon Bay just to the east of Dover Harbour.
This place was used to light possible enemy ships coming by night. The Langdon battery, on the top of the cliff, could shoot these ships. In this map you can see these strategic placements:
The Langdon battery doesn’t exists any more. A Coastguard station was built in its place. The remains of this search light batteries are still in quite good condition. To visit them, you have to climb down a zigzag stair carved on the vertical wall of the cliff. Worth the effort, I think. Initially there were three, but a cliff fall destroyed the one closest to the harbour. Those cliff falls are very dangerous, and it is advisable not to get very close to the edge, something I did a few times.