Recently returned from a week in the Lake District. On one of the hills outside Keswick is a stone circle called Castlerigg.
The stones are of a local metamorphic slate, set in a flattened circle, measuring 32.6 m (107 ft) at its widest and 29.5 m (97 ft) at its narrowest. The heaviest stone has been estimated to weigh around 16 tons and the tallest stone measures approximately 2.3m high. There is a 3.3m wide gap in its northern edge, which may have been an entrance. Within the circle, abutting its eastern quadrant, is a roughly rectangular setting of a further 10 stones. The circle was probably constructed around 3200 BC (Late Neolithic/Early Bronze-Age), making it one of the earliest stone circles in Britain and possibly in Europe.
It is important to archaeoastronomers who have noted that the sunrise during the Autumn equinox appears over the top of Threlkeld Knott, a hill 3.5 km to the east.
Recently a Roman fort has been discovered to the south of the stone circle, dissected by the narrow track. Nothing above ground is visible and it is hard to see how the presence of te fort influenced the name of the area as some have suggested.