Bishop’s Waltham was a medieval palace used by the wealthy Bishops of Winchester. Also on the site is the Bishop’s Waltham town museum, in a farmhouse adapted from the palace’s lodging range.
There are extensive ruins of this large palace still standing.
I happened to be nearby in the early morning, so had a look over the wall, but was not able to get inside.
Worth a look if you are in the area. Admission free.