Dating back to around 1300 BC, this is the finest existing example of a domed tholos tomb, made by filing down the layers of breccia blocks to create the smooth interior. It's wonderfully misnamed, since it has little to do with the mythical Atreus, or with his equally mythical son, Agamemnon, but the interior is truly awe-inspiring, with a 40m-long passage leading to the vast beehive-shaped chamber. Spot the original bronze nails that once held the door in place.
