Another of Cornwall's great aristocratic estates, Trelowarren has been in the hands of the Vyvyan family for six centuries and sprawls over 1000 acres of land between Goonhilly and the Helford River. Much of the estate has now been given over to timeshare properties and holiday cottages, but there are several woodland walks that are open to the public – including one to Halliggye Fougou, a mysterious underground chamber on the site of an old Iron Age hillfort.
There's a fee to park on the estate, but English Heritage members qualify for free parking. While you're here, it's well worth dropping in for lunch at the estate's upmarket restaurant, New Yard.