We went there four years running in the 80's when it was a bit grotty by today's standards, but had a look a couple of years ago and the whole place has been transformed (for the better). It's a really interesting area with the dockyard at St. Nazaire which was raided by the Commandos in 1942 (they destroyed the dry dock gates).The campsite itself was a military camp for the gun crews manning the 88mms across the road. The reception building has all the hallmarks of a military guardroom! La baule is easily reached with longest beach you'll find in Europe, St.Nazaire itself is a typical modern town (almost completely rebuilt after the war) although the old port remains as was, complete with submarine pens. Over the St. Nazaire bridge are some pretty villages and the whole area is well worth a good look at. If you go, do walk across the bridge, it's well worth the effort!
Good luck and happy caravanning!
Regards
Derek