30th November 2008, 12:05 PM
There was a substantial wooden trough found in association with a burnt mound in the Gwent Level in 2006. I seem to recall that it dated through dendrochronology to the early Bronze Age. I'm not sure why sauna seems like an odd conclusion; you get very similar deposits to burnt mounds forming at the back of traditional Scandanavian summer houses, they chuck out the cold stones.