I think you'd really enjoy exploring around some old castles. I have been to tons of them, mostly in England from having an English other half. It kind of comes with the territory! I imagine you could hop over to Europe fairly cheaply from Thailand, right? I have a friend from England who regularly goes to Thailand for vacations.
It's really fun to see how poncy people lived way back in the day (and how some still live) in these huge stone structures.