East Kalimantan: reefs, rivers and a capital in the making

East Kalimantan is the largest economy in Borneo and the province where Indonesia is building its future capital. Balikpapan is an oil town that turned into a clean, confident city; Samarinda is a river port with a busy waterfront and a hinterland of coal and timber. Between them, the Mahakam river drains a basin the size of the Netherlands.

The province's travel reputation rests on the Derawan islands, a scattering of atolls and reef flats off Berau where green turtles nest, jellyfish have lost the ability to sting, and the boat ride from the mainland is still part of the adventure. Inland, the forest of Wehea and the karst of Sangkulirang remain for travellers who have already seen the coast.

Where East Kalimantan fits in a Borneo trip

East Kalimantan is the easiest part of Borneo to combine with the rest of Indonesia. Balikpapan has frequent flights to Jakarta, Surabaya, Makassar and Denpasar, and the province is the northern terminus of the Trans-Kalimantan road. That makes it a natural entry point for anyone crossing the island or heading up to North Kalimantan.

It is also a province of two holidays in one. The Derawan islands offer a reef-and-turtle week that competes with Sulawesi and Raja Ampat, while Samarinda and the Mahakam offer a river-and-culture itinerary built around Kutai history and Dayak villages. Most visitors choose one or the other; a ten-day trip can comfortably do both.

The province is also changing faster than any other in Kalimantan. The relocation of the national capital to Nusantara has brought new highways, a new airport and a construction boom, while the old oil and coal economy continues around Balikpapan. For travellers this means better infrastructure each year, but also that maps and advice dates quickly; confirm road and flight details close to departure.

The Derawan archipelago and Berau

Derawan, Maratua, Sangalaki and Kakaban form the core of the Berau marine area. Derawan itself is a small island with a village, guesthouses and a reef that starts at the jetty. Maratua is larger, with a lagoon, a channel famous for big fish, and a handful of dive resorts. Sangalaki is a green turtle nesting island, and Kakaban holds a landlocked lake where jellyfish have evolved without stinging cells.

Access is from Berau: fly to Kalimarau airport (BEJ), drive two to three hours to Tanjung Batu, then take a boat. Speedboats run scheduled and charter services, but seas can cancel crossings between December and March. Diving is the main activity, though snorkellers see plenty on the house reefs, and the turtle hatchlings at Sangalaki are the reason many people come.

Getting there: Balikpapan, Samarinda and Berau

Sultan Aji Muhammad Sulaiman Sepinggan airport in Balikpapan (BPN) is the province's international gateway, with direct flights to several Asian cities and a dense domestic network. Samarinda is two to three hours north by road; buses and shared taxis run constantly. Berau is an hour by air from Balikpapan, or a long day by road.

Nusantara, the new capital, sits in Penajam Paser Utara between Balikpapan and Samarinda. Construction has changed the road network and will continue to do so, so check routes before driving. Public transport inside the province is bus- and angkot-based; for the Derawan coast and the interior, a rented car with a driver is the practical option.

Driving times are deceptive. Balikpapan to Samarinda is about 130 kilometres but takes two to three hours on a busy two-lane road, and the same distance inland can take twice as long after rain. Flights between Balikpapan and Berau take under an hour and are usually the better choice if your time on the islands is short.

• Balikpapan (BPN): main airport, oil-town base, Sepinggan
• Samarinda: Mahakam riverfront, Kutai culture, road hub
• Berau (BEJ): gateway to Derawan, two hours from Tanjung Batu
• Tanjung Redeb: Berau's capital, markets and supplies

The Mahakam, Kutai and the interior

The Mahakam rises in the mountains of North Kalimantan and runs roughly 980 kilometres to the Makassar Strait. For centuries it was the artery of the Kutai kingdoms, whose Hindu inscriptions at Muara Kaman are among the oldest written records in Indonesia. Tenggarong, upstream from Samarinda, holds the Mulawarman museum in a former royal palace.

Further upstream, the river passes through Dayak territory and the limestone country around Sangkulirang, where caves hold hand stencils thousands of years old. Travel here is slow and requires permits and local guides. The Wehea forest, managed by the Wehea Dayak community, is the best-known example of community-run conservation in the province.

When to go and what to expect from the weather

The dry season, June to September, is the reliable window for Derawan: calm seas, good visibility and easy crossings. It is also the busiest time, and the small islands have limited beds, so book ahead. Dive conditions stay good into October in most years.

The wet season brings rain, choppier crossings and occasional closures, but the forest and rivers are at their best and prices fall. Balikpapan and Samarinda are year-round cities. If your trip depends on reaching Maratua or Kakaban, build in a spare day for weather delays.

Water temperature stays close to 28 °C all year, so a 3 mm suit is enough for most divers. Visibility on the outer reefs is best in the dry season, while the muck sites near Berau reward anyone who likes small creatures. Note that some resorts close for maintenance in January and February.

Costs, beds and travelling with care

Balikpapan and Samarinda have the province's widest range of hotels, from IDR 300,000 guesthouses to business hotels above IDR 1,000,000. On Derawan, simple rooms start around IDR 350,000 and dive resorts on Maratua charge by the package, usually including meals and transfers.

East Kalimantan is a resource province, and travel here means engaging with that reality. Ask before photographing mining or plantation sites, respect village rules in Dayak communities, and use reef-safe practices in the Derawan marine park. Turtles and jellyfish are protected; touching or chasing them is both illegal and damaging.

On the islands, waste is a genuine problem: bring a refillable bottle, refuse single-use plastic where you can, and choose operators that carry their rubbish back to the mainland. On land, dress modestly in towns, use your right hand for greetings and money, and ask before entering a mosque or a longhouse during a ceremony.

Questions people actually ask

How do I get to the Derawan islands?

Fly to Berau (BEJ), drive two to three hours to Tanjung Batu, then take a speedboat. Some resorts arrange the whole transfer; independent travellers can use scheduled boats from Tanjung Batu in the morning.

Is Kakaban's jellyfish lake safe to swim in?

Yes, the jellyfish in Kakaban have lost their stinging cells. Visitors must still avoid sunscreen, fins and aggressive movement, and the lake has a carrying capacity that limits daily numbers.

Can I visit Nusantara, the new capital?

Access is restricted while construction continues, and most of the site is not open to tourists. The road network around Penajam Paser Utara is open, but expect checkpoints and changing conditions.

How long should I stay on Derawan?

Five nights gives you time for Derawan, Maratua, Sangalaki and Kakaban without rushing. Three nights covers the main dive sites but leaves no margin for bad weather.