Two Chalcolithic chambered tombs near Lisbon, Portugal. In its first phase it was a simple rock-cut tomb and subsequently a passage grave with partially corbelled chamber was added. The rock-cut tomb contained decorated slate plaques and other material of Late Neolithic or early Chalcolithic type with a date of c 2300 BC. The later tomb, which blocked the entrance to the earlier tomb, contained about 150 burials, Beaker pottery, Palmela points, and a tanged dagger. Its date is 1690 BC.