Dated at around 3200BC, Castlerigg stone circle is thought to be one of the earliest stone circles in Britain, and indeed in Europe. Its 38 stones make up a slight oval with 10 smaller stones forming an inner rectangle. While we can only guess as to their purpose, more recent sightings of strange lights in the sky above the stones only add to their mystery.
At 104ft/32m at its widest Castlerigg is not all that large but it is well preserved. It is also noteworthy in having a number of stones set in a rectangle within the Circle. The stones themselves are impressive many reaching 6ft/2m in height.

There is a tradition that it is impossible to count the number of stones within Castlerigg; every attempt will result in a different answer. This tradition, however, may not be far from the truth. Due to erosion of the soil around the stones, caused by the large number of visitors to the monument, several smaller stones have ‘appeared’ next to some of the larger stones. Because these stones are so small, they are likely to have been packing stones used to support the larger stones when the circle was constructed and would originally have been buried. Differences in opinion as to the exact number of stones within Castlerigg are usually down to whether the observer counts these small packing stones, or not; some count 38 and others, 42. The ‘official’ number of stones, as represented on the National Trust information board at the monument, is 40.

In the early 20th century, a single outlying stone was erected by a farmer approximately 90m to the south west of Castlerigg. This stone has many linear ‘scars’ along its side from being repeatedly struck by a plough, suggesting that it was once buried below the surface and also why the farmer dug it up. It is not possible to say whether this stone was originally part of the circle, or just a naturally deposited boulder.