1851 - Topographical Dictionary of Scotland, Samuel Lewis
CASTLETOWN, a village, in the parish of Olrick, county of Caithness, 5 miles (E. by S.) from Thurso; containing 477 inhabitants. This is a remarkably neat and thriving village, situated near the south coast of Dunnet bay. It owes its advancing prosperity to its proximity to the valuable quarries of Castlehill, of which the stone is known by the name of Caithness pavement. A church has been built at the east end of the village, in which, also, is the parochial school; and a female school has been partially endowed.