Chûn Castle is an Iron Age hillfort on the summit of Chûn Downs, commanding extensive views north and north-west to the Atlantic Coast and south towards Mounts Bay. Pottery evidence from excavations carried out in the late 1920s and early 1930s suggests that the main period of occupation extended from the 3rd century BC until the early 1st century AD, with a possible re-occupation in the 5th or 6th centuries AD. It is roughly circular in plan with two impressive stone walls, each with an external ditch. Within the interior are the remains of several stone walled round houses, heavily disturbed by later activity.