Coordinates: 50°22′08″N 4°43′50″W / 50.3689°N 4.7305°W Prideaux Castle /ˈprɪdᵻks/ is a quadrivallate Iron Age hillfort situated atop a 133 m (435 ft) high conical hill near the southern boundary of the parish of Luxulyan, Cornwall, England, United Kingdom. It is also sometimes referred to as Prideaux Warren, Prideaux War-Ring, or Prideaux Hillfort.
This site should not be confused with the historically linked, but quite distinct Elizabethan stately home called Prideaux Place, in Padstow, Cornwall.
The remains of the first and second circular ramparts are quite distinct, although overgrown with trees on the north and east sides. They appear to be constructed of earth and rubble. The third rampart is only fragmentarily represented, but easily traced, due to the vegetation. A fourth, outermost wall is discerned on aerial photographs, or on the 1888 Ordnance Survey map. This outermost wall is in the form of an incomplete "D" shape, extending to the west and south on the downhill slope of the site. There are two entrances, typical of the small hillfort, located on the eastern and northern side (i.e., opposite the fourth wall), where it is most wooded. There is no evidence of dressed stones. The palisade and any internal structures would have been of wooden construction and must have perished without trace.