Balikpapan is a seaport city in East Kalimantan, Indonesia. Located on the east coast of the island of Borneo (Kalimantan), the city is the financial center of Kalimantan and the main gateway to the new capital of Indonesia. Balikpapan is the city with the largest economy in Kalimantan with an estimated 2016 GDP at Rp 73.18 trillion. The city has both the busiest airport and seaport in Kalimantan, namely Sultan Aji Muhammad Sulaiman Sepinggan Airport and Port of Semayang. With a population of 645,727 as of 2018, Balikpapan is the second most populous city in East Kalimantan, after Samarinda. Balikpapan has been consistently ranked as one of the most liveable cities in Indonesia.