A Palaeolithic flint tool found in West Sedgemoor is the earliest indication of human presence in the area. The Neolithic people exploited the reed swamps for their natural resources and started to construct wooden trackways, including the world's oldest known timber trackway, the Post Track, dating from about 3800 BC. The Levels were the location of the Glastonbury Lake Village as well as two Lake villages at Meare Lake. Several settlements and hill forts were built on the natural islands of slightly raised land, including Brent Knoll and Glastonbury. In the Roman period sea salt was extracted and a string of settlements were set up along the Polden Hills. The discovery at Shapwick of 9,238 silver Roman coins, known as the Shapwick Hoard, was the second largest ever found from the time of the Roman Empire. A number of Saxon charters document the incorporation of areas of moor in estates. In 1685, the Battle of Sedgemoor was fought in the Bussex area of Westonzoyland at the conclusion of the Monmouth Rebellion.