According to a website covering the local area (Kenfig.org at http://www.kenfig.org.uk/geology ), the rock outcrop of Gwely'r Misgl consists of Keuper Breccia which, it is indicated, was formed
Uploaded to Geograph by eswales on 23 September 2014
Photo © eswales, 23 September 2014. Licensed for reuse under this Creative Commons licence