Dolmen de Penhap is a small but worthwhile Neolithic passage grave on Île-aux-Moines, built from granite and marked with carved motifs including axes and a goddess figure. It is less famous than the great megalithic sites around Carnac and Locmariaquer, but that is part of its charm.
The dolmen works best as a stop on an island walk, adding a deep prehistoric layer to the Gulf of Morbihan's coastal scenery.