Pekanbaru is the capital of Riau, a province in Indonesia on the island of Sumatra. It has an area of 632.26 km² with a population of 950,571, making it Sumatra's third largest municipality, after Medan and Palembang.It is located by the Siak River, which drains to the Strait of Malacca that makes Pekanbaru has direct access to the busy strait and was long known as a trading port. The city is divided into 12 subdistricts. This city is served by the Sultan Syarif Kasim II International Airport and Sungai Duku Port that is located by the Siak River. A settlement has existed on the site since the 17th century. In the late 19th century, the city was developed to serve the coffee and coal industries, and the Dutch built roads to help ship goods to Singapore and Malacca.