Sitting high up on the hills above Keswick is maybe the most perfectly placed of all the stone circles. This circle sits on a flat topped hill that is itself completely surrounded by mountains. 110 feet in diameter there are 38 good sized stones making up the circle. To the southeast, on the inside, and up against the circle, there is a rectangle made up of 10 stones. I have not seen this elsewhere. I have read several ideas as to what was going on there but it is just another of those stone puzzles.
Castlerigg reminds me a bit of Sunkenkirk, they are both impressive circles with impressive views.
Keswick is a lovely lakeside resort town and can be very crowded. As a result, Catlerigg can draw lots of folks doing the tourist thing and that can be a bit of a bummer. Still it is a must see if you are in the Lake District. And, for any James Bond fans, the James Bond Museum is in town and was really good fun.