Of greater importance than any of these in the pre-Doric period were the feudal states of the Peloponnesus. The strongest among these was the royal house of the Atridæ, upon whose glory terrible legends cast a dark and bloody shadow. From their capital at Mycenæ they ruled over the whole of Argolis; chieftains in Tiryns, in Argos and on the coast of the peninsula of Parnon acknowledged their authority. The remains of the citadel of this royal family are still preserved. The hill on which this citadel stood is surmounted by a small circular wall, and lower down is surrounded by a mighty wall which everywhere follows the edge of the cliff, and which in some places is built of rough layers of massive stones, elsewhere of carefully fitted polygonal blocks, but also for considerable stretches of rectangular blocks, in horizontal courses. On the southwestern side is the principal gate, the famous Gate of the Lions, which takes its name from the oldest extant remains of sculpture in Greece. In the triangular gap in the wall above the lintel an enormous slab of yellow limestone is fitted; it is divided in the middle by a perpendicular column, on either side of which stands a lioness. In this acropolis Schliemann found graves with human remains, with vessels of clay, alabaster, and gold, ornaments of rock-crystal, copper, silver, gold, and ivory. Near the Gate of the Lions begin the walls of the lower city, which stood on the ridge extending from the western declivity of the citadel to the south. In this lower city are a number of remarkable subterranean buildings, sepulchres and treasure houses of the ancient monarchs. The best preserved and largest of these is the noteworthy round building known as the “treasure house of Atreus” (also as the “grave of Agamemnon”), which is especially interesting on account of its _tholos_, or interior circular vault.