Chapel Carn Brea is an elevated Hercynian granite outcrop, owned by the National Trust at the southern edge of the civil parish of St Just, Cornwall, England, United Kingdom.

[2] Chapel Carn Brea is often described as the first hill in Cornwall (from a westerly perspective) and rises 198 metres (650 ft) above sea level.

The hill is an important historical site showing evidence of neolithic and early Bronze Age activity, as well as the remains of the thirteenth century chapel from which it is named.

In 1868 and 1879 William Copeland Borlase excavated the site and built a new cairn which was destroyed by the building of a Second World War radar observation post, which was manned by the Royal Air Force.

[5] The Old Cornwall Society continues to light a beacon fire for the summer solstice on 23 June each year.