The Irrawaddy River is the principal river of Myanmar, running through the centre of the country. Myanmar's most important commercial waterway, it is about 1,350 mi (2,170 km) long. Originating from the confluence of the N'mai and Mali rivers, it flows from north to south before emptying through the Irrawaddy Delta in the Ayeyarwady Region into the Andaman Sea. Its drainage basin of about 156,000 mi2 (400,000 km2) covers 61% of the land area of Burma, and contains five of its largest cities.