Tarakan is a city on an island of the same name in East Kalimantan, and the largest city of the province of North Kalimantan.
Tarakan is 100km south of Nunukan, and also serves as a visa-free border-crossing between Indonesia and the Malaysia town of Tawau in Sabah.
Although Tarakan is the only independent city (kota) of the province of North Kalimantan, and the most populous city by far (population about 220,000), it is not the capital. The provincial capital is Tanjung Selor.
A less mind numbing way of travel to Tarakan is to take the ferry service which plies a few times a day between Nunukan and Tawau, and a twice daily flight that goes between Nunukan and Tarakan. To get into Tawau this way, take the 11AM ferry (which usually waits to depart until it's full, which can mean it leaves at noon) from Tawau to Nunukan. The Labuan Express ferry tends to be the cleanest. The journey will take 45 minutes to an hour and it costs 40 Ringgit. After getting through Indonesian immigration, catch a minibus (RP 20,000 to charter the whole thing, but be prepared to bargain) to the airport, 15 minutes away. There's a Kalstar plane (ATR propeller plane which can seat 50 people) that arrives at 13:30 or 14:00 to Tarakan. Tickets are RP 258,000 including tax and can be purchased at the airport. The journey takes less than 15 minutes.
Of course you can travel to Tarakan from the Indonesian side (mainly going through the oil city of Balikpapan). From Balikpapan there are three to four flights daily except Sundays. By the way, if you do choose to go through Balikpapan airport, try the "Nasi Sop Buntut" at the Blue Sky restaurant on the second floor of the airport. Right beside the viewing gallery. Excellent stuff. Probably the best in Kalimantan.
To/from Tawau: One departure daily except on Sunday from Tawau. M.V. Indomaya sails every Monday, Wednesday and Friday at 11:30, while M.V. Tawindo M.V Labuan Express departs every Tuesday, Thursday and Saturday at 10:30. Tickets cost RM130 to RM140 (depending on which ferry you get on) one-way and travelling time is 4 hours (and that's not counting the usual 1 hour delay in departure time).
Be prepared to pay porters to haul your bags for you. On the Malaysian side, RM10 should be sufficient, on the Indonesian side about 20,000-30,000 rupiah for a couple suitcases. In Tawau, the ferry docks at the Customs jetty behind the fish market. In Tawau, the ferry docks at Tengkayu port, which is close to the city centre. The jetty, in this case, is a very long walk to the customs/immigration building. The minute the ferry docks (at either port), a crowd of porters will jump on board and hustle to grab your bags.
2nd-order administrative division
Primary administrative division