This skull from the site of ancient Jericho is covered with molded plaster and has eyes of shell. The people of Jericho stored decorated skulls such as this one, which dates to between 6000 and 7000 bc, beneath their floors in what appears to have been a complex form of ancestor worship. Jericho is one of the earliest known settlements of the Neolithic, the period of human prehistory associated with the domestication of plants and animals and the establishment of villages.