The famous granite quarries lie in the hills to the south of Aswan, just off the main road. They were the main source of granite in Egypt, exploited from earliest times right through to the Greco-Roman Period. The Fourth Dynasty pharaohs who built the pyramids at Giza (2613-2494 B.C.) were among those who exploited the quarry. Nine great slabs of granite, weighing fifty-four tons each, were extracted to support the ceiling of the so-called King's Chamber of the Pyramid of Khufu-(Cheops). Red granite was chosen for the Valley (or Granite) Temple of Khafra (Chephren). Black granite was quarried for the lower levels of the outer casing of the Pyramid of Menkaura (Mycerinus).