Balikpapan is a seaport city on the east coast of the island of Borneo, in the Indonesian province of East Kalimantan. Two harbors, Semayang and Kariangau (a ferry harbour), and Sultan Aji Muhammad Sulaiman Airport are the main transportation ports to the city. The city has a population of 701,066, making it the second-largest city in East Kalimantan, after Samarinda.