I visited several years ago, it's a real hidden gem. Spent a fun hour or so implementing a prime sieve on a BBC BASIC computer - an adventure for someone in their early thirties! My friend and I also banged our heads against that old text-based Hitchhikers Guide to the Galaxy game, trying but failing to get even as far as getting onto the space ship. At the other end of the spectrum it was also my first experience of a VR helmet.