The German artillery battery at Longues-sur-Mer may not have been the most powerful in Normandy, but it was one of the best located to oppose the landings of 6 June 1944. Installed slightly back from the edge of a sixty-meter-high cliff, it was positioned directly opposite the Allied fleet and right between Omaha and Gold landing beaches.

The coastal battery at Longues-sur-Mer, part of the Atlantic Wall coastal fortifications, was built by the German navy in the first half of 1944 and completed in four months. It consisted of four 150mm guns in concrete bunkers, and one 120mm gun. In May 1944 the battery was operational, but the firing command post built on the edge of the cliff did not yet have all the equipment necessary for calculating effective fire against naval targets.

On D-Day, the Longues-sur-Mer battery delivered a protracted duel with the Allied fleet, forcing some of the vessels to retreat in order to avoid being hit. However, the five guns of the battery were gradually silenced, some being destroyed by direct hits. Finally, British troops landing at Gold Beach took over the position on 7 June, capturing the survivors of the garrison of 180 men.

Today, the site is one of the best-preserved in France and the only one where you can still see some of the original cannon, capable at the time of firing shells weighing 45kg at a distance of 22km. The view from the firing command post dug into the cliff offers a vast panorama over the Bay of the Seine.