Castle Downs, Cornwall
{{Short description|Hill in Cornwall, England}}
{{Use dmy dates|date=April 2022}}
{{Infobox mountain
| name = Castle Downs
| photo = File:Castle an Dinas 1.JPG
| photo_caption = Castle Downs. The hillfort is just visible on the summit.
| elevation_m = 216
| prominence_m = 67
| isolation=
| listing = TuMP
| location = Cornish Killas, Cornwall, UK
| coordinates = {{coord|50.4248|-4.8938|type:mountain_region:GB|display=inline,title}}
| grid_ref_UK = SW945623
| topo = OS Landranger 200, Explorer 106
}}
Castle Downs is a dome-shaped hill, {{convert|216|m|ft}} high, located in mid Cornwall, UK.Ordnance Survey 1:25,000 Explorer map series, No. 106 There is a major hillfort, Castle an Dinas, on the summit and extensive and panoramic views across the county to both north and south coasts.[http://www.historic-cornwall.org.uk/a2m/iron_age/hillfort/castle_an_dinas/castle_an_dinas.htm Castle-an-Dinas], historic-cornwall.org.uk; accessed 4 September 2013.
The open summit of Castle Downs is located just north of the A30 road in mid Cornwall, about 2 miles east-southeast of St Columb Major, 2 miles northeast of Indian Queens and about 7 miles west-southwest of Bodmin. About 1½ miles to the east is the sister hill of Belowda Beacon (227 m).Ordnance Survey 1:50,000 Landranger map series, No. 200
The major summit feature of Castle an Dinas is a massive Iron Age hill fort comprising 3 concentric ramparts and ditches that were probably originally surmounted by wooden palisades. The main entrance is to the southwest. Within the castle are 2 Bronze Age barrows. The hillfort has been partially damaged by a, now closed, 20th century wolfram mine.
Legend has it that the site was one of the seats of the Duke of Cornwall and, according to folklore, it is also where Cador, Duke of Cornwall and Ygraine, King Arthur's mother, were killed.