Dolmen du Mané-Kerioned, France
The Dolmen du Mané-Kerioned is a set of three dolmens in corridor surrounded by small menhirs . The construction has been dated to 3500 BC. One of the dolmens has engravings on some of the stones inside. This style of wall engravings similar to the patterns observed on the back of the cover slab of the large dolmen of the Table des Marchand of Locmariaquer. Rectangles are observed there looking like mazes and wavy lines like snakes.
This is a really nice site, well worth a visit for the three dolmens and to see the engravings.