The summit has an Ancient British Iron Age or late Bronze Age hill fort. It is this which the hill is named after - Caer Caradog in Welsh meaning Caradog's fort. Local legend has it that this was the site of the Battle of Caer Caradoc, the last stand of Caractacus against the Roman legions during the Roman conquest of Britain, and that after the battle he hid in the cave near its summit. Others say his last stand was in the locality but that this was one of his fortresses.