The 1846 Flagstaff House, the former residence of the commanding British military officer, is the oldest Western-style building in Hong Kong. Some (including the Court of Final Appeal Building and the Hong Kong Observatory) retain their original function, and others have been adapted and reused; the Former Marine Police Headquarters was redeveloped into a commercial and retail complex, and Béthanie (built in 1875 as a sanatorium) houses the Hong Kong Academy for Performing Arts.