The submarine base Keroman plays a major part in the history of Lorient. The city played a strategic role in the Battle of the Atlantic during the Second World War. The German Navy U-boats started operating in the Atlantic early. In June 1940 the war started, affecting Lorient directly. Very soon, the Germans started building the three Keroman submarine base on a 26-acre area of land south of the city to protect their submarines from the English bombing. The construction required the participation of 15 000 workers. The three bases have impressive dimensions and were constructed and subsequently coined KI, KII, KIII. The submarine base area has changed over the years and is now is open to the public - offering an amazing blend of history, water sports, and tourism and future projects still to come. See the Submarine pens, climb on top of the former anti-aircraft tower on top of the base, and enjoy the views to the harbour. You also have the opportunity to visit a Daphnee-class submarine from 1961.