Hey FourWinds, that's a damn fine site.

Sadly the sauna/burnt mound in Moseley Bog is little more than a small mound by a stream littered with blackened stones. I could send you a picture if you want, but there's not much to see.

There's a pdf document from Mike Hodder about burnt mounds being used to heat water at:

http://www.birmingham.gov.uk/Media/Moseley%20Bog%20handout.pdf?MEDIA_ID=70278&FILENAME=Moseley%20Bog%20handout.pdf&NOCACHE=TRUE