Carn Bugail is a circular cairn at the top of Cefn Gelligaer with a burial ciste in the centre. About three miles north west of Deri which is off the A469 and southeast of Merthyr Tydfil. The area around Gelligaer Common has a number of cairn sites and the remains of a Roman Road.
Link: Carn Bugail & Gelligaer standing stone courtesy of youtube.com
Link: Gelligaer Common - an archaeological surpise by Frank Olding courtesy of Cadw.