Hakata Bay is a bay in the northwestern part of Fukuoka city, on the Japanese island of Kyūshū. It faces the Tsushima Strait, and features beaches and a port, though parts of the bay have been reclaimed in the expansion of the city of Fukuoka. The bay is near the site of the Mongol invasions of Japan of 1274 and 1281; both invasions are sometimes referred to as the "Battle of Hakata Bay."