Kemp Howe is well worth a visit, but thermals are always a good idea in Cumbria.
I've got no plans of the area I'm afraid, but the following Web page by someone called Andy Burnham (the name rings a bell) suggests that most of Kemp Howe remains buried under the railway embankment. It also has a good aerial photo of the circle:
http://easyweb.easynet.co.uk/aburnham/eng/kemphw.htm
I like the idea that one day we could recover the circle. It's not dead, just restings.
Kammer x