Another early scene was the Dunkirk recreation which was shot at the beachfront in Huelva, Spain. To reflect the cloudless skies of summer of 1940, many upward-facing shots were filmed over Spain, while downward-facing shots were almost all below the clouds, over southern England, where farmland is distinctive. However 1940 camouflage made it difficult to see the aircraft against the ground and sky, so a cloud background was used where possible. Only one Spitfire was relocated to Spain to stand in for the RAF defenders. After filming began, the English weather proved too unreliable and filming was moved to Hal Far and Luqa Airfields in Malta to complete the aerial sequences.