Green Island is a small (145 m long x 50 m) artificial island in the Red Sea at the southern mouth of the Suez Canal. Green Island was a fortress built by the British Army (probably by British Troops in Egypt or Rear-Admiral, Alexandria, Royal Navy) to protect the Suez Canal from air and sea attack during World War II. This waterway was of enormous strategic significance for Britain at this time. Located three kilometers south of Port Ibrahim and four kilometers south of the city of Suez and the mouth of the Suez Canal, the fortress was built on a bed of stable corals and made out of reinforced concrete. It consisted of a one-storey building with a large courtyard.