Located on the former site of the 15th-century Edo Castle, the Imperial Palace is the official residence of Japan's royal family. First constructed in 1888, the palace was rebuilt several times, most recently in 1968. The current building is a steel-framed, two-story structure that incorporates traditional Japanese architectural elements, such as a hipped and gabled roof. The palace is surrounded by landscaped gardens, a moat, and original castle ramparts. Available by appointment only, tours of the palace are led in Japanese, although English audio guides are provided. The Outer and East gardens are open to the public at no charge.