Pulau Sejahat, located off the north-eastern coast of Singapore, was designated as a British defence outpost. Its role was to protect the Johor Straits and the naval base at Sembawang. The military encampment on the island — including gun emplacements, water tanks and observation towers —was constructed during the late 1930s as part of British preparation for a war in Singapore. The island was returned to the Singapore Government in 1972, after the British military’s withdrawal from Singapore.