Two of the characters arrange to rendezvous at the Boating Lake in Battersea Park. But when the scene comes, they actually meet up at the boat pond in Battersea Funfair -- not at all the same place!

The latter didn't make as much sense anyway, as admission to the Park was and is free, but getting into the Funfair cost extra. Why pay just to meet someone?

(By the way, the Boating Lake is still there, but the Funfair closed at the end of 1974. The Lake is about four-five times the size that the Funfair was, and the pond was a tiny little place.)