Green Island is an island off the northwest coast of Kennedy Town, Hong Kong Island, separated by the Sulphur Channel. A smaller island nearby to the east, uninhabited, is called Little Green Island (). Administratively, the two islands are part of Central and Western District. Buildings Green Island is largely uninhabited and at the east coast is Green Island Reception Centre and Green Island Police Station. On the top of the hill is an office of the Marine Department and a lighthouse southwest guides the ships in Sulphur Channel. Lighthouse compound The buildings of the Green Island Lighthouse Compound were declared as monuments, In 2008. The historic buildings include the two lighthouses built in 1875 and 1905 and the European quarters of the lighthouse compound. These three buildings are individually Grade II historic buildings. The first lighthouse, tall and constructed of granite, began operation on 1 July 1875. There are two cross-shaped openings on its wall for ventilation and lighting. The openings resemble gun-posts like those found in medieval European castles. These are of the same construction as those found on the Cape Collinson Lighthouse at Siu Sai Wan, Hong Kong Island. It was later disused in 1905 because the building was too small to carry the lens from the Cape D'Aguilar Lighthouse. Construction began on a second lighthouse in 1904, completed in 1905, which was originally intended to house the Cape D’Aguilar light. Built of granite and concrete, sitting beside its predecessor, the newer lighthouse is tall, painted white, with a steel-caged lantern on top. A concrete spiral staircase with rails gives access to the lantern room. An upper floor was added to the keeper's house in 1923 and the lighthouse was automated in the 1970s. The two lighthouses, along with Cape D'Aguilar Lighthouse, Waglan Island Lighthouse and Tang Lung Chau Lighthouse (Kap Sing Lighthouse) are the only prewar lighthouses remaining. Living quarters and house The keeper's house has a flat roof and is designed in an 'L' shape. The house has arched windows and hanging eaves. The quarters was converted to the Police Recreation Centre for an unknown time. It is currently leased to the Wu Oi Christian Centre as a youth drug treatment rehabilitation centre. Green Island Reception Centre The Green Island Reception Centre () was historically used as a temporary reception centre for Vietnamese refugees. As of 1997, it was used to accommodate Vietnamese illegal immigrants