Definitely a POW camp in Watnall.
On holiday in Majorca in the 1960s my cousin and I met two German couples. We got chatting and it turned out that one of the men had been a POW at Watnall during WW2. He told us that he had been very well treated, and had become very fond of England and its people. Good thing, because this particular conversation took place when we were stuck in a small lift between floors for nearly an hour!