Penstowe Castle, also called Kilkhampton Castle, was a medieval fortification built near Kilkhampton, Cornwall, England, possibly during the years of the civil war in the 12th century known as the Anarchy.

The precise date of Penstowe Castle's construction is uncertain, but it was built during the years of the Anarchy in the mid-12th century,[1] either by Robert, 1st Earl of Gloucester, feudal baron of Gloucester, who was certainly the tenant-in-chief of the manor of Kilkhampton, or by his tenants and relatives the Grenville family (possibly Sir Richard I de Grenville (d.post 1142) of Neath Castle, Glamorgan), which held the manor of Kilkhampton and the manor of Bideford in Devon from the Honour of Gloucester.

Stowe House was the Grenvilles' residence at Kilkhampton, demolished and rebuilt in grand form in 1679 by John Granville, 1st Earl of Bath (1628-1701).

Kilkhampton Castle was built to a motte and bailey design, positioned on a knoll and protected by steep slopes on the north and south sides.

[3] The configuration of baileys is unusual, although similar to nearby Eastleigh Berries Castle.