of masked men, stars, and geometric motifs, which may have been connected to religious beliefs. Bronze Age Many of the villages built during the Early Bronze Age (3200–1950 BC) included simple water infrastructures, as well as defensive fortifications probably designed to protect against raids by neighboring nomadic tribes. At Bab al-Dhra in Wadi `Araba, archaeologists discovered more than 20,000 shaft tombs with multiple chambers as well as houses of mud-brick containing human bones, pots, jewelry and weapons. Hundreds of dolmens scattered throughout the mountains have been dated to the late Chalcolithic and Early Bronze Ages. Although writing was developed before 3000 BC in Egypt and Mesopotamia, it was generally not used in Jordan, Canaan and Syria until some thousand years later, even though archaeological evidence indicates that the inhabitants of Transjordan were trading with Egypt and Mesopotamia. Between 2300 and 1950 BC, many of the large, fortified hilltop towns were abandoned in favor of either small, unfortified villages or a pastoral lifestyle. There is no consensus on what caused this shift, though it is thought to have been a combination of climatic and political changes that brought an end to the city-state network. During the Middle Bronze Age (1950–1550 BC), migration across the Middle East increased. Trading continued to develop between Egypt, Syria, Arabia, and Canaan including Transjordan, resulting in the spread of technology and other hallmarks of civilization. Bronze, forged from copper and tin, enabled the production of more durable axes, knives, and other tools and weapons. Large, distinct communities seem to have arisen in northern and central Jordan, while the south was populated by a nomadic, Bedouin-type of people known as the Shasu. New fortifications appeared at sites like Amman's Citadel, Irbid, and Tabaqat Fahl (or Pella). Towns were surrounded by ramparts made of earth embankments, and the slopes were covered in hard plaster, making the climb slippery and difficult. Pella was enclosed by massive walls and watch towers. Archaeologists usually date the end of the Middle Bronze Age to about 1550 BC, when the Hyksos were driven out of Egypt during the 17th and 18th Dynasties. A number of Middle Bronze Age towns in Canaan including Transjordan were destroyed during this time. Iron Age During the Iron Age (1200–332 BC), Transjordan was home to the Kingdoms of Ammon, Edom and Moab. The peoples of these kingdoms spoke Semitic languages of the Canaanite group; their polities are considered