Castle an Dinas, St Columb Major

Castle an Dinas is an Iron Age hilltop fort located near St Columb Major in Cornwall with three concentric rings of defensive earthworks positioned at about 260 meters elevation. The oval-shaped structure used the natural slope of the land to strengthen its defensive position.

The fort was built during the Iron Age but was also occupied during the Bronze Age, as shown by burial mounds found within the enclosure. In the 20th century the site was used for mining before becoming protected as an archaeological monument.

The site holds connections to Arthurian tales, with local traditions identifying it as a hunting lodge of King Arthur and the location of Gorlois's death.

The site is accessible through marked paths starting from a parking area that allow visitors to walk around the entire terrain. Information boards on site explain the structure and the different periods when the fort was in use.

Between 1916 and 1957 wolfram was mined on the site, with the mineral Russellite being discovered there for the first time. Excavations in the 1960s then redirected attention back to its archaeological importance.