Tiled roofs first replaced thatched roofs in ancient Mesopotamia.[2] Fired roof-tiles occur from as early as the 3rd millennium BC in the Early Helladic House of the tiles in Lerna, Greece.[3][4] Debris found at the site contained thousands of terracotta tiles which had fallen from the roof.[5] In the Mycenaean period, roof tiles are documented for Gla and Midea.[6]