“Picts used the promontory of Cleaved Head as a safe refuge. On the promontory they built a wooden fort with ditches at the landward end. Below the fort the Picts used the beach as a natural harbour. The Picts were known as great fishermen. Many carved symbol stones from the Pict Age show a “Pictish Beast” which is thought to be a dolphin.”
Banffshire Maritime and Heritage Association.
(Another example of later peoples using something that was already there.)