A grand, if a little ruinous, monument on the edge of the Foret de Quenecan, on high ground with superb views over the lower ground of the Blavet river valley out the the east.
Bot er Mohed means the fairy grotto apparently.
It's a bit trashed on one side and you can't get into it anymore due to undergrowth and jumbling up of stones, but it still looks good and complete. There seems to be no stones missing. On one side there is a wall of seven continuous large slabs.