Rock basins at Treryn Dinas


“Castle Treen”, the rocky part of the Logan Rock headland, hosts numerous rock basins. Their formation due to the decomposition of granite along the mechanical action of rainwater and weathering on weak feltspar crystals. In the past there has been a lot of discussions whether they were natural or made by the Druids who dwelled at Treryn Dinas, whatever the reason for being there, the rock basins make a great watching spot and fantastic reflections of sky on water

Doctor Borlase imagined that the rain water caught in the rock basons was used for lustration and purification; and that by the quantity, colour, motion, and other apperances the priests judged of future events and dubious cases.

(from Blight, A week at the Land’s End, 1861)

“The rock basons rounded hollows (…) also pointed at showing that the Druids had some connections with this spot. Doctor Borlase imagined that the rain water caught in this vessels was used for lustration and purification; and that by the quantity, colour, motion, and other apperances, the priests judged of future events and dubious cases. This basons may be seen on almost over high granite cairns in Cornwall. Dr Borlase inclined to the opinion that some of them were artificial, but Dr Paris, an eminent geologist, says “they are unquestionably the result of operation of time and the elements, and have never been formed by any agents excepts those that Nature employs in the decomposition of granitic masses.

Whether they are natural or artificial, matters little as regards the use the Druids made of them, though it appears they generally used rocks in a natural state, the use of tools to work them into shape being forbidden. Thus “Dr Paris” argument that they were not druidic because natural, tend rather to defeit himself. Each visitor, however, will probably have his own opinion on the subject.”