This is the location of an open air museum dealing mainly with the Atlantic Wall of WW2. It comprises a wide ranging collection of military artifacts of the period and include a rare WW1 coastal fort. The museum ranges for a kilometer or so on either side of the marker - there is a very good collection of photos. It is a sobering thought that, in 1944, much of the coast from Norway to Spain looked like this! (For life and death inside thiis type of bunker see 'D Day Through German Eyes' by Eckhertz. It was not a pretty sight).