The world’s largest archipelago, Indonesia is made up of more than 17,000 islands, yet many Brits know just the one. And that is why its tourist board’s current message is simple: ‘Look Beyond Bali.’ From Sulawesi to West Papua, stops range from low-lying desert isles with reefs, white-sand beaches and palm trees to large, mountainous islands with opportunities for trekking, wildlife safaris, scuba diving, cultural adventures and much more.

Lombok: Just east of Bali, adventurers alight here to tackle the dizzying heights of Mount Rinjani, an active volcano which can be scaled via various paths. Longer treks descend into the crater and finish at its lake and hot springs. There are plenty of beaches for a relaxing end to a trek, including Senggigi, which has some upmarket options, and Kuta (not to be confused with Bali’s Kuta, this one is a quiet fishing village offering surfing, diving and other watersports). Just off Lombok are the car-free Gili Islands: Gili Trawangan (known as the party island), quiet Gili Meno and Gili Air, which lies somewhere in-between.

New product: The Legian Lombok is set to open in 2018, with 39 guestrooms, eight villas and five ultra-private Joglo houses, the latter with a multi-tier infinity pool, dining pavilion and wellness facilities.

Java: Most visitors to Java will spend some time in the chaotic capital of Jakarta, which has both skyscrapers and Dutch colonial architecture. Also popular is cultural Yogyakarta, a centre for Javanese art like batik paintings, shadow puppet shows and music, and nearby Borobudur – the world’s largest Buddhist monument. Pegged for development and ripe for adventure is East Java’s Mount Bromo National Park. Its eponymous volcano is more accessible than many of the country’s peaks and the smoking crater looks out over a sea of sand to many more sizzling cones. In the far southeastern corner of Java is world-class surf at Grajagan Bay, also known as G-Land and home to surf camps from April to October.

Sell it: Hayes and Jarvis has a nine-day trip of Java from £1,882pp for travel in June with flights. Highlights of Indonesia includes Jakarta, Bandung, Yogyakarta, Solo, and Bromo.

Sumatra: Jungle, wildlife, wild beaches and more volcanoes await. Top attractions include Gunung Leuser National Park’s population of orangutans, Sumatran tiger, rhinoceros and elephants. Lake Toba, the world’s largest crater lake, has captivating green vistas along with traditional Batak villages with their exaggerated pointed roofs, hot springs and the steep island of Samosir at its centre. Trekkers can also head to Sianok Canyon, with its sheer cliffs and underground caves and bunkers, a legacy from Japanese occupation in World War Two. The Karo Highlands also offer tribal culture, waterfalls.

Sell it: Intrepid Travel has a Sumatra Adventure itinerary which includes trekking Gunung Leuser National Park, climbing Sibayak for a picnic and time in Lake Toba.

Sulawesi: This strange-shaped island’s four limbs are mountainous, cloaked in dense jungle and surrounded by rich seas. Wakatobi National Marine Park comprises 1.4 million hectares and is recognised as having the largest number of reef and fish species in the world, with over 50 spectacular dive sites. Inland are rare species such as nocturnal tarsiers and flamboyantly-coloured maleo birds. The island is also home to several unique cultures whose traditions have survived modernisation thanks to the impenetrable topography. The Toraja highlanders live in unique wooden houses with huge boat-shaped roofs and have elaborate funeral rites involving colourful processions and burial sites carved into rocky cliffs and guarded by life-like effigies.

Stay: The five-star Wakatobi Dive Resort operates it own charter flights from Bali and offers villa accommodation, a fine dining restaurant, spa and activities like kayaking, village and cooking workshops.

Komodo National Park: Declared a World Heritage Site and a Man and Biosphere Reserve by UNESCO, over 30 years ago, Komodo National Park encompasses 29 volcanic islands (including Rinca, Padar and Komodo) and is home to approximately 2,500 Komodo dragons and otherreptiles, birds and mammals. The park’s terrain is exceptionally diverse, featuring mountainous hillside, tropical rainforests, grass-woodland savannah and pristine white-sand beaches which lead to sea rich in marine biodiversity and plied by many liveaboard dive boats.

Sell it: Dive Worldwide offers an 11-day liveaboard onboard the Mermaid II from £2,895pp, including all meals and tanks and one night in Bali.

Flores: The 670km Trans-Flores Highway runs the length of this fertile island, crossing mountains, passing emerald paddy fields, traditional villages and tumbling waterfalls. The volcanic spine soars to 2500m and torrential wet seasons result in a lushness that accounts for the island’s name. Islanders are mostly Catholic, which gives it a slightly different cultural feel. Aside from many hidden beaches the three craters of the extinct Kelimutu volcano are a top destination: each has a different, vibrantly-coloured lake which constantly changes its hue.

New product: AYANA will be launching the first and only five-star resort on Flores Island’s Waecicu Beach, AYANA Komodo Resort, Waecicu Beach opens summer 2018 with 12 suites and 189 premium guest rooms.

Kalimantan: The Indonesian portion of Borneo is by far the largest part of this biologically diverse island, the third largest in the world. The main reason to alight here is the vast swatches of jungle, criss-crossed by countless rivers and home to bucket list wildlife like proboscis monkeys and orangutans. Tajung Putting National Park is home to crocodiles and 220 species of bird as well as Camp Leakey, an Orangutan Preservation Centre.

Sell it: Audley Travel’s 14-day Heart of Indonesia: Borneo and Java tour is from £3,460pp and includes a cruise around Tanjung Puting National Park and visiting orangutan feeding stations.

Raja Ampat: Situated off West Papua, Indonesia’s most eastern Island, Raja Ampat is an archipelago of over 1,500, mostly unnamed small islands, cays, and shoals surrounding the four main islands of Waigeo, Batanta, Salawati, and Misool. Meaning ‘The Four Kings’, the territory is home to around 75% of the world’s marine species, including pigmy seahorses manta rays, dugong, turtles, tuna, giant sea clams, giant trevallies, snappers, batfish and barracudas. On land are pristine beaches and various bird species including the bird of paradise.

Book it: Audley Travel has a 15-day Cruising Raja Ampat itinerary from £7,445. Guests will visit fishing villages, discover wildlife and swim and snorkel. Ends with a few days relaxing on the white-sand beaches of Lombok.