Guam
Guam's best-known wreck-diving site, in Apra Harbor near Piti, where the WWI German raider SMS Cormoran and the WWII Japanese cargo ship Tokai Maru lie touching each other underwater.
SMS Cormoran, a WWI German commerce raider, was scuttled at Guam in 1917 after the US entered the war and rests on her starboard side at about 34 m; she was listed on the US National Register of Historic Places in 1975. The Japanese cargo ship Tokai Maru, sunk in 1943, came to rest leaning against Cormoran's propeller shaft and was separately listed on the NRHP in 1988. The National Park Service describes the combined site as probably the most popular wreck-diving site on Guam, the only place where WWI and WWII shipwrecks can be dived touching each other on a single dive. Source: Wikipedia (SMS Cormoran, Tokai Maru), US National Park Service.