One of the more interesting places I visited was the Brockhampton Estate and in particular the late 14th century moated Manor House of Lower Brockhampton. The gatehouse is relatively recent being around 1540! The estate was gifted to the Trust in 1946 by John Lutley whose family had owned it for 20 generations.
The house had been tenanted until recently.
I would definitely recommend a visit. There are plenty of estate walks. In Shropshire English Heritage have a property called Stokesay Castle that is well worth investigating as another example of pre-15th century architecture that is on a less grand scale than your typical castle.