The first human visitors to Dorset were Mesolithic hunters, from around 8000. The first permanent Neolithic settlers appeared around 3000 BC and were responsible for the creation of the Dorset Cursus, a monument for ritual or ceremonial purposes. From 2800 BC onwards Bronze Age farmers cleared Dorset's woodlands for agricultural use and Dorset's high chalk hills provided a location for numerous round barrows. During the Iron Age, the British tribe known as the Durotriges established a series of hill forts across the county—most notably Maiden Castle which is one of the largest in Europe.