The Merville Battery and Museum

The Merville Gun Battery is a decommissioned coastal fortification in Normandy, France, which was built as part of the Germans' Atlantic Wall to defend continental Europe from Allied invasion. It was a particularly heavily fortified position and one of the first places to be attacked by Allied forces during the Normandy Landings commonly known as D-Day. A British force under the command of Lieutenant Colonel Terence Otway succeeded in capturing this position, suffering heavy casualties.

Source: Wikipedia