Low-lying wetland region of Somerset in southwest England, famous for the preservation of remains in peat. Ancient trackways have been revealed and, with techniques such as pollen analysis and radiocarbon dating, it has been possible to establish the sequence of human and climatic development in the area. Permanent settlement occurred only on small 'islands' raised above the level of the marsh (e.g. the Iron Age villages of Glastonbury and Meare), but wooden tracks crossed the wet areas. The earliest discovered is the Sweet track dated to the Neolithic c 3600/2800 BC; after that tracks continued to be built at various times in the 3rd millennium BC. There was a long hiatus in track construction, perhaps because drier conditions made them unnecessary, but with climatic deterioration in the Late Bronze Age there was a new phase of track construction c 900-450 BC (alternatively, c 1100-500 BC).