Windsor Castle maybe? I liked that a lot as a young teenager. It’s a pretty town, too.
Woking and Guildford are at the heart of the commuter belt, which is why my first thought was London.
Would Portsmouth and its historic dockyard and old ships be of any interest? Again, something I loved as a teenager but I was a bit nerdy…
Is there any interest in Jane Austen? Her birthplace at Chawton near Alton isn’t too far away.
It’s interesting that none of us are actually suggesting things within Woking or Guildford.. I think they’re both perfectly pleasant towns. Guildford has an interesting modern cathedral that featured in The Omen (I think) and there are all the usual shops but I’ve never felt the need to stop and explore further because I always thought of them both just as places en route to London! But they are well-located for a large area of southern England.