Enough with Bali. There are 18,000 other islands in Indonesia and they are equally gorgeous!

Sumatra isn't quite off-the-beaten-track, but it sure feels like it. Perhaps the sheer magnitude of the island's geography ensures there's enough for everyone. Unending rainforests, so many beaches, so many volcanoes, a general sprinkling of offshore islands framing both its coasts – and mountainous roads that make for a slow travel scene.

Amazing places to visit in Sumatra:

A gateway to Sumatra's rainforests, and home to a conservation project for Sumatran orangutans.

Things to do in Bukit Lawang: Jungle trekking, tubing.

Along with Mentawai Islands, Nias is considered to be one of the best places to surf on the planet.

Things to do in Nias: Surf, learn how to surf, or just enjoy the stunning, remote waters. Also, on Mentawai, you can't really miss the indigenous Mentawai culture.

Home to two active volcanoes, Mount Sinabung and Mount Sibayak, the latter of which last erupted in 2013.

Things to do in Berastagi: Hike up the volcanoes.

A small cluster of islands off of Sumatra's east coast. A popular getaway for Singaporeans and Malaysians due to excellent ferry connectivity.

Things to do in the Riau islands: Be a beach bum.

A stunning caldera lake created by one of the planet's most significant volcanic eruptions. The island in the centre of the lake (Tuk Tuk) has a strong backpacker scene and plenty of cheap, decent accommodation.

Things to do in Lake Toba: Swim in a volcanic lake, cycle around the island and beyond, enjoy the warm Batik hospitality of the locals.

Practically untouched, Jambi's rainforest is fascinating, and not just because it's home to the last remaining Sumatran tigers.

Things to do in Jambi: Hike to the top of Sumatra's highest peak, explore Kerinci-Seblat National Park.

The world's most infamous volcano is off Sumatra's southern coast, and can be accessed via Lampung (bus+boat trip) or from West Java (Anyer and Carita). It's actually much better (cheaper+easier) to get here from Java instead, but if you are in Lampung, you can also plan a trip to Way Kambas National Park, home to the Sumatran rhinos and elephants.

Other amazing things to do in Sumatra: Dolphin watching in Kiluan Bay, Bukittingi, diving in Banda Aceh and the street food in Medan.

Get in: There are six airports in Sumatra, and all of them offer direct flights to both Kuala Lumpur and Jakarta. Here's a list of the airports, roughly from North to South – Banda Aceh, Medan, Pekanbaru, Padang, Palembang and Batam (on Riau islands).

Ferry: This is the hard way to reach Sumatra from Java. A public ferry connects southern Sumatra to Java. The ferry terminal on Sumatra is in Bakauhueni, which connects to Merak on Java. From Bakahueni, the nearest transport hub is in Bandar Lampung, which is a cheap, 90-minute bus ride away.

Suggested itinerary: Start your journey from North Sumatra, which means get in via Kuala Lumpur. Here's a pretty decent route to see it all, if you have the time and the intention. Expect to spend at least 3 weeks on this itinerary.

Fly in to Banda Aceh > Bukit Lawang (hike through the jungle for 10 days, or take a bus, via Berastagi) > Berastagi > Lake Toba > Jambi > Riau Islands > Padang (fly from Batam) > Mentawai and Nias > Lampung > Krakatoa > Jakarta

Java: Indonesia's beating heart

Most of Indonesia's population lives on this slinky, wonderful island. A lot of Indonesia's heritage is rooted in the history of Java, so expect temple complexes, traditional artefacts and a lot of art; and because this is Indonesia, all of it set against the backdrop of a massive, fuming volcano.

Amazing places to visit in Java

The capital city is one of the largest in the world. However, there isn't so much to do for travellers, except a great introduction to urban Indonesia.

The gateway to Mt. Krakatao (also see in Sumatra), Anyer provides great access to the volcano. Get on a boat-trip to the Krakatao for an unparalleled view of the volcano. The beach in Anyer is also very pretty, and there is a lighthouse worth checking out.

While you are in Anyer, also visit the Ujung Kulon National Park, one of the most incredible lowland rainforests of the world, with inland volcanoes and an interesting coastline.

The train from Jakarta to Yogyakarta (pronounced Jog-jakarta) is a backpacker favourite: cheap, comfortable and a great way to see the Javanese countryside. In Yogyakarta, you will find a major chunk of Java's tourists. The city provides great access to the temples of Borobodur and Prambanan and has a pretty cool political history.

Things to see in Yogyakarta: The Borobodur ruins, the ancient temples of Prambanan, the city life in Yogyakarta and the Kraton Palace complex.

East Java delves into serious volcano hiking and jungle life. Surabaya is the easiest access gateway – connecting to all major attractions in the area. Several travel agencies in Yogyakarta can also arrange multi-day tours (usually 3-4 days).

Things to do in East Java: The two big volcanoes: Mount Bromo and Mount Semeru, Sukamade beach (for turtle nesting) and the Baluran National Park (for the savannah wildlife and beaches).

Get in: Jakarta and Surabaya are the two main airports, for West and East Java respectively. There are also ferries to and from Sumatra (discussed above) and Bali: Gilimanuk (East Java) to/from Gianyar (Bali)

Suggested itinerary: You will most likely start/end your journey in Jakarta. Here's a suggested route. Expect to spend at least 12 days in Java to see it all.

Fly in to Jakarta > Anyer (for Krakatao and Ujung Kulong) > Train to Yogyakarta (via Jakarta) > Surabaya > Mt. Bromo and Mt. Semur> Bekol Savanna and Bama Beach> Onwards to Bali

Kalimantan (Borneo): As Jurassic as it gets

The island of Borneo is shared by both Indonesia and Malaysia, with a much larger chunk on the Indonesian side. The people of Kalimantan are collectively called the Dayak, and speak more than 70 distinct languages. The island houses one of the oldest rainforests in the world, and is home to several endemic species of wildlife, including the Borneon orangutan, leopards and prehistoric species of birds. Outside its jungles, and the rivers within them, Kalimantan is rimmed by unchartered waters with spectacular beaches.

Not for the faint of heart, Kalimantan's jungles and rivers have been around longer than the human race. But if you like surprises, please delve in.

Amazing places to see in Kalimantan

Even if it's the only thing you do here, get yourself on a klotok in Tanjung Puting National Park to Camp Leakey. A klotok is a double-decker boat that traverses the waterways of the jungle. The journey is typically two days long, with an overnight dock in the forest where you sleep aboard.

Tanjung Puting National Park is one of the easiest places in the world to spot an orangutan. Colourful tropical wildlife, including gibbons, kingfishers and hornbills are also fairly easy to see.

The bloodlines of East Kalimantan flow through its rivers and waterways, which support countless floating villages, some of which are centuries old. A major chunk of tourists to the Kalimantan island will inevitably wind up in East Kalimantan, usually to enjoy a river cruise on Indonesia’s second largest river, Sungai Mahakam, or to get a taste of the culture of the Apo kayan people.

East Kalimantan is actually largely a hub for the Indonesian oil and gas industry. However, East Kalimantan's hinterlands are definitely fascinating and the forest cover is immense, where it's easy to spot orangutans and other primates. There's also some spectacular diving off the east coast – especially off the Derawan island, which is also famous for a freshwater lake infested with jellyfish!

Things to do in East Kalimantan: River cruising up the Mahakam for a peek into the contemporary Dayak culture. Don't expect too many traditional longhouses (or headhunters). Also diving and beaching on Derawan island in the Celebes Sea.

Get in: Balikapan and Tarakan are the gateways to East Kalimantan, with air connectivity to other Indonesian cities. Tarakan is also connected to Malaysian Borneo via ferry to/from Tawau.

West Kalimantan is largely unchartered. Infrastructure connectivity is poor, but it does exist. And if Dayak culture is your main draw, this is where you need to be. West Kalimantan has the highest concentration of traditional longhouses. The locals are friendly and curious as they are not really used to seeing too many tourists.

Get in: Pontianak will most likely be your point of entry (via flight). If travelling by road from other parts of Kalimantan, expect to spend quite a long time on the road.

Other things to see in Kalimantan: Meratus mountains in South Kalimantan, Dayak Culture in Central and East Kalimantan.

Suggested itinerary: There is none. Most tourists will spend a week on the island and split their time between a couple of places in East Kalimantan and a klotok tour in Tanjung Pitung. It would take months to explore Kalimantan properly. West Kalimantan would be a good place to start.

Eastern Indonesia: Sulawesi, Nusa Tengarra, Maluku and Papua

The largest of the eastern islands is called Sulawesi, formerly known as Celebes. The easiest access point is via the airport in Makassar, which is well connected to the rest of the country.

Things to do in Sulawesi: Experience the animist Toraja culture in Tana Toraja; dive in any of the famed spots on the island, notably Una Una, Wakatobi and the Togean islands.

Flores is home to the famed Komodo dragons. The namesake Komodo National Park is one of eastern Indonesia's biggest attractions. Another fascinating place to visit on Flores is a three-coloured volcanic lake in Kerimutu – which spontaneously goes from blue to green to deep red. The diving, unfortunately, has diminished in recent years due to the shortsighted "dynamite-fishing" practices around the island.

Get in: Labuanbajo Airport (also known as Komodo Airport) is great for quick access to the Komodo Island. There are several other airports (the biggest one is in Maumere, with direct connectivity to the rest of Indonesia. Ferries are a popular way to reach Flores from Bali – Labuanbajo, Maumere, Larantuka and Ende, all have boat connectivity.

Most islands in Nusa Tengarra are rarely visited, with a slight exception of Flores and Lombok. So, expect endless diving and white-sand beaches as perfect as possible.

Lombok in Nusa Tengarru is the gateway to eastern Indonesia and is a relatively chill escape from the jaded Bali scene. There is frequent ferry connectivity from Padang Bai in Bali to Lembar (4-5 hours). There's also an airport, with great flight connectivity to most of Indonesia. Gili Islands are also nearby and are increasingly becoming a backpacker favourite, again especially for those looking for an alternative to Bali.

Other great islands in Nusa Tengarra: West Timor, Sawu Islands, Sumbawa (especially for surfers) and the Alor archipelago.

Between Sulawesi and Papua, Maluku is very, very away from the usual. They are also known as the spice islands, for obvious reasons. There is an airport on Ambon, a beautiful, untouched island. Most people visit Ambon on a dive-trip from nearby islands. These islands are home to beautiful, green dormant volcanoes and several amazing beaches. Accommodation can be quite sparse, especially outside Ambon.

Other islands in Maluku: Halmahera, Ternate, Obi and Kei Islands.

Not to be confused with Papua New Guinea, which is an independent country, Papua makes up the eastern border of Indonesia. The biggest draw is the traditional cultures that are still around and also Lorentz National Park, which is also the biggest national park in Asia.

Get in: Jayapura is the main airport, and the easiest way to access Papua. There is boat connectivity from all neighbouring islands, which is worth it if you have the time.

Transportation in Indonesia

Public transportation in most of Indonesia is cheap and reliable. Most of the locals get around on public buses, trains and ferries, so connectivity exists in even the remotest parts of Indonesia, even if it's sometimes slow and infrequent.

Local transport: Motorcycle taxis, known as a ojek, are available across the breadth of the country, especially in the hinterlands where four-wheelers are not that prevalent.

Buses: Usually the cheapest way to get around overland. There are local buses and minibuses between every city, town and village. Private buses (air-conditioned, reclining seats) run between most tourist destinations, especially on Java, Bali and Sumatra. For local buses, tickets can either be purchased on the bus or at the main bus station. Private buses are usually booked through travel agents.

Trains: Train connectivity is great on Java, patchy in Sumatra and non-existent on all other islands. Tickets can be purchased online, up to two days in advance.

Ferry: There's ferry connectivity between all islands. Between main tourist spots, there is frequent (daily/hourly) connectivity - often on diesel-powered tourist boats. Shipping Vessels operated by Pelni, Indonesia's national shipping carrier, connects all the islands on a monthly or fortnightly basis. Click here for a route map. Tickets can be purchased through travel agents and from booking offices on ferry terminals throughout the country.

Other water transportation includes fishing boats (mainly for diving trips) and longboats (river boats, mainly on Kalimantan). River ferries also ply up and down on several rivers, carrying passengers, vehicles and cargo.

Visa on arrival: Indonesia offers a visa on arrival to citizens of many countries, including India. The cost is $35 (usually payable in US dollars) for a 30 day visa. Here's the complete list of countries for the VoA program.

This article attempts to provide a detailed, but still very incomplete glimpse of Indonesia's many, many islands. If you've visited these places, especially in Eastern Indonesia, please share what you can: photos, reviews, travelogues and guides.

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