kinds. These include earthen henges, timber circles, and stone circles. Stone circles are found in most areas of Britain where stone is available, with the exception of the island's south-eastern corner. They are most densely concentrated in south-western Britain and on the north-eastern horn of Scotland, near Aberdeen. The tradition of their construction may have lasted for 2,400 years, from 3300 to 900 BCE, with the major phase of building taking place between 3000 and 1,300 BCE. These stone circles typically show very little evidence of human visitation during the period immediately following their creation. For this reason the historian Ronald Hutton suggested that the circles were not used for rituals that left archaeologically visible evidence, but may have been deliberately left as "silent and empty monuments". The archaeologist Mike Parker Pearson argues that in Neolithic Britain, stone was associated with the dead, and wood with the living. Other archaeologists have proposed that the stone might not represent ancestors, but rather other supernatural entities, such as deities. In the area of modern Wiltshire, various stone circles were erected, the best known of which are Avebury and Stonehenge. All of the other examples are ruined, and in some cases have been destroyed. As noted by the archaeologist Aubrey Burl, these examples have left behind "only frustrating descriptions and vague positions". Most of the known Wiltshire examples were erected on low-lying positions in the landscape. In the area south of Swindon, a town in northern Wiltshire, at least seven stone circles are reported as having existed, often only a few miles distant from one another; the Day House Lane Stone Circle is for instance 2 km north-east of the (now destroyed) Fir Clump Stone Circle. Although the vestiges of the Day House Lane Stone Circle survive, all of the other known northern Wiltshire circles have been destroyed. Description Based on his observations in the 1890s, the antiquarian A. D. Passmore estimated that the circle had originally been up to in diameter. He also thought that it would have been of a slightly irregular shape, with its diameter varying at different points. Based on the surviving stones and their spacing, Passmore suggested that the circle would have once contained over thirty stones. The surviving stones used were sarsen. In the 1890s, Passmore recorded nine stones surviving as part of the circle, but by the early 21st century there were only five. Passmore's investigation