In 1943, during the Second World War, HM Fort Roughs was constructed by the United Kingdom as one of the Maunsell Forts, primarily to defend the vital shipping lanes in nearby estuaries against German mine-laying aircraft. It consisted of a floating pontoon base with a superstructure of two hollow towers joined by a deck upon which other structures could be added. The fort was towed to a position above the Rough Sands sandbar, where its base was deliberately flooded to sink it on its final resting place.