T1-323 was the tail number (T1 = "705 Kokutai") of the plane carrying Japanese Admiral Isoroku Yamamoto on an inspection tour throughout the South Pacific when he was shot down and killed by American fighter aircraft during World War II. On 18 April 1943, T1-323, a Mitsubishi G4M1 (model 11) "Betty" long-range bomber, and a sister craft departed from Rabaul, were headed to Bougainville in the Solomon Islands off New Guinea, when a task group of P-38s intercepted and downed the planes over Buin, a large Japanese army base in southern Bougainville.
In addition to Yamamoto, commander of the Japanese Navy, T1-323 carried the following passengers and crew on that day:
The wreck of T1-323 remains as a tourist attraction in the Bougainville jungle near Moila Point, a few kilometers off the Panguna-Buin road. Signposts can be found near the village of Aku, 24 km outside Buin. A path to the wreck has been cut through the jungle, an hour's walk from the road. Other artifacts from the crash site, including the outer wing panel and the Admiral's seat, reside at the Isoroku Yamamoto Memorial Hall & Museum in Nagaoka, Japan.