Penhallam is the site of a medieval manor house surrounded by a protective moat. It was designated as a Scheduled Monument in 1996 and is now in the guardianship of English Heritage.The site is a grass-covered ruin showing the complete ground-plan of the manor. The manor dates from the late 12th century and was abandoned during the mid-14th century. Penhallam is one of only four such moated medieval manor sites in Cornwall and it consists of a quadrangle of buildings around a central courtyard.