Berck-sur-Mer, France, summer of 1940. Three combat engineers from the 10. Panzer-Division take a look at a defused British Mk XIV (or possibly the upgrade, Mk XVII) naval mine, the contact horns removed and the 145 kg TNT charge lying next to it.
Mine warfare was very much a thing during WW2, all nations with coasts using naval mines both to protect their territory, to disrupt enemy shipping (as part of a blockade), and to sink enemy warships and merchant ships. There were several types of mines, the most common being the contact mine like the one above. That type was moored and submerged just under the surface, a mechanism adjusting the length of the mooring wire as the tide rose and fell. The mine had a number of horns, and when one of those was struck by a ship, the main charge exploded, the resulting damage crippling or sinking the ship. Other types of mines reacted to the magnetic field of a ship, or the sound of its propellers. Naval mines were the cause of loss of ships and lives long after the war, as unswept mines continued to be a danger to shipping.
Berck-sur-Mer was a small fishing town in the Pas-de-Calais region which had become a resort in the mid-19th century, when a hosptial for the treatment of tuberculosis was built there, the sea air thought to be beneficial for the patients. The town was damaged in 1944, as Allied air raids in preparation of D-Day hit German coastal installations, mainly as a diversion in order to draw German attention from the landing beaches in Normandy. The town recovered, and is now a holiday resort.