Castle-an-Dinas is one of the largest and most impressive hillforts in Cornwall, sited in an imposing strategically important trading route, on the summit of Castle Downs with extensive and panoramic views across central Cornwall to both north and south coasts, standing 700 feet above sea level.

The defences comprise of three massive circular stone and earth banks with outer ditches, together with traces of a slighter fourth bank. The site was occupied between 400 b.c and a.d 150.

There are two Bronze Age barrows in the central enclosed area and these may be traces of the first human use of this hill, although recent surveys have suggested that there is a levelled-off platform between the outer and inner banks and ditches which may represent the traces of even earlier (Neolithic) use.

Excavations carried out in the 1960s in the interior suggested that the main period of use was during the Iron Age, when the ramparts would have stood at their highest, probably topped by a wooden palisade. The main entrance lies on the south-west side, and the gateway had a cobbled surface. There is a wet, marshy area inside the enclosed area, suggesting that it might once have contained a well, making it possible to live on the site. It is likely that there would have been timber roundhouses and other structures and work areas.

Within the fort are the remains of two Bronze Age round burial mounds (2000-1500 b.c). The barrows, graves of local chieftains or nobles, would have been built around 1500 years before the hillfort, and appear to have been respected and revered by the Iron Age people and not damaged during their occupation of the hill.

A truly fabulous and impressive site that is easily reached from the road, driving up a track to a dedicated car park and a short walk up to the ramparts.

~ Later History ~

King Arthur is associated with this area. Castle an Dinas is reported to have been the hunting seat of Arthur when he rides in the local Tregoss Moor hunt. 

1478 ~ William of Worcester visits Cornwall  in his history he wrtse how the legend states that Castle an Dinas was the place where Gorlois, Duke of Cornwall died. Gorlois was the husband of King Arthur's mother.

1646 ~ during the English Civil War, Royalist troops led by Sir Ralph Hopton camp at the fort for two nights. They hold a Council of War here and make the decision to surrender to the Parliamentarians. The vote is almost unanimous with only Major General Webb and Hopton himself voting against it. They surrender a few days later at Tresillian Bridge, near Truro

1660s ~ John Trehenban, a 21 year old resident of St Columb Major, murders two young girls.

Trehenban joins the hunt for the murderer, riding on horseback following the bloodhounds. His hat blows off and the dogs are so interested in its scent that they will not leave it alone. Eventually this forces his confession.

He is sentenced to imprisonment and his punishment is to be locked in a cage in the hillfort to be left to starve to death.

Starving, he begs a passerby for food but all they have is a few tallow candles. He takes and eats them.

The Parish Register lists the murder of Anne, daughter of John Pollard and Loveday, daughter of Thomas Rosevear of St Enoder.

1876 ~ The open cast  tin mining on the north side of the hill that had continued for many hundreds of years finally comes to and end.