This question has defeated two local historians, so I'm glad we've got
a member with a family connection to the camp!

It's listed on pages such as http://www.kg6gb.org/pow_camps_in_uk_-
_251_to_1026.htm as being in Bushey Road. I wonder whether the fact
that it's got the highest number on the list means that it was the
last to be opened? I have been told that the playing fields in Bushey
Road were the location of anti-aircraft guns and barrage balloons
earlier in the war.