The city of Jericho is a Palestinian city located near the west banks of the Jordan River. Jericho is believed to be one of the oldest inhabited cities in the world, with evidence of settlement dating back to 9,000BC. The first settlement was built near the Ein as-Sultan spring, between 10,000 and 9,000BC. Due to increasing global temperatures around this time, agriculture and permanent residence become possible, leading to the development of permanent villages. By about 9,400 BC, the town of Jericho had grown to more than 70 homes, and may have housed over 1000 people. Famously, the early town was surrounded by a 3.6 metre high wall, known as the wall of Jericho.