Capacity: 5,500

Location: Tokyo Bay Zone

Odaiba Marine Park will host the triathlon competition along with open water swimming races. The venue within the park will exist temporarily for the Games. Odaiba is an artificial island in Tokyo Bay across the Rainbow Bridge from central Tokyo. "Daiba" means "fort" in Japanese - Odaiba was initially built as a series of six island fortresses in 1853 to protect the city from attack. The area became a major commercial, residential, and leisure area in the 20th century as transportation options from central Tokyo to the area improved. It is one of the city's most popular destinations for visitors, famous for its sunset views.