The Nile Valley is first inhabited in the Lower Paleolithic Period (ca. 300,000 B.C.–90,000 B.C.). Neolithic people continue to create stone tools, and exploit domesticated plants and animals (7000–4500 B.C.). In the ensuing millennia many forms of art flourish, including jewelry (faience beads), ceramic vessels, geometric figures, and pottery, much of which is found in tombs. Hierakonpolis in the south, the largest Predynastic settlement known, is the center of political control. The pyramids of Giza and Saqqara arise in the Old Kingdom (ca. 2649–2150 B.C.), one of the most dynamic and innovative periods in Egyptian culture. Power decentralizes during the First Intermediate Period (ca. 2150–2030 B.C.), only to be unified again by the Theban king Mentuhotep II in the Middle Kingdom (ca. 2030–1640 B.C.).