Farnham Castle 
Description
There's been a castle on this site since at least the 12th Century, though the ruins that are here today date from a later version of the castle. It's a stiff climb up to the top of the castle walls, but from the top there are excellent views across the site and the wider countryside. The attached Bishops Palace is open occasionally to look around, though not on the day I visited - they were hosting a wedding.
Charge
Free
Getting There
Latitude: 51.219027; Longitude: -0.802517
What3Words: odds.procures.fairly
