With more than 17,000 islands – ranging from palm-fringed islets to the leviathan bulk of Sumatra – Indonesia's natural diversity is showcased amid more than 1.9 million sq km straddling the equator and stretching from the Indian Ocean to the Pacific. Volcanic peaks rise from lush jungle, the underwater world is revealed in the planet's finest diving locations, and surprising wildlife ranges from giant reptiles to gentle denizens of the forest.

Tanjung Puting National Park

Willdlife watching and river adventures combine in this massive 4150 sq km park in central Kalimantan, the Indonesian southern part of Borneo. Rustic but comfortable river boats travel up the Sungai Sekoneyer, stopping at orangutan feeding stations during a three-day journey en route to Camp Leakey, a rehabilitation centre where orphaned and formerly captive orangutans are trained to live in the wild. Stellar birdlife including darting kingfishers and regal hornbills is often revealed along the river's banks, and local operators including Borneo Orangutan Adventure Tour can arrange private trips on the Sekonyer's signature two-storey teak houseboats dubbed klotok.


Menjangan Island

Located just off Bali's northwestern tip, Pulau Menjangan ('Deer Island') is one of Indonesia's most accessible locations for both experienced divers and adventurous snorkelling fans. The surrounding Bali Barat National Park ensures protection for twelve different dive sites, and the crystalline waters showcase sheer walls, caves and a spectacular drop off. Expansive corals and shapeshifting schools of tropical fish create an underwater ambience akin to swimming in a giant aquarium – a marine spectacle achievable even by relatively novice snorkellers. For experienced divers the fascinating 19th-century wreck of the Anker lies at a challenging depth of around 50m.


Raja Ampat Islands

Remote near the northwestern tip of far-flung Papua Island, the scattered waters of Raja Ampat host the world's greatest diversity of marine life. Above a translucent ocean, rounded hills enrobed in tropical forest surround a labyrinth of compact coves and improbably small islets, providing sublime diversion to the underwater spectacle. Manta rays and epaulette sharks drift through a technicolour seascape of pristine coral, while shoals of barracuda and parrotfish patrol the diverse marine terrain punctuated with underwater walls, peaks and ridges. Snorkelling, kayaking and birdwatching are all essential attractions for non-divers, and live-aboard boat cruises – often on Bugis-style heritage schooners – are the best way to explore Raja Ampat.


Kelimutu National Park

Best discovered at sunrise after a meandering minibus journey from nearby Moni, three intensely coloured volcanic lakes sit atop the summit of Kelimutu on the eastern island of Flores. Two of the exceptionally deep crater lakes regularly change colour – driven by the continuous leaching of different minerals – and the indigo smudge of a Flores dawn illuminates contrasting hues ranging from brown and orange through to black and red. All the while, Kelimutu's third lake is daubed an iridescent shade of turquoise, glowing through the half-light slowly revealing Kelimutu's sparse lunar landscape.


Harau Valley

Easily reached from the Sumatran mountain town of Bukittinggi, the Harau Valley is fringed by soaring limestone cliffs up to 100 metres high and enlivened by the Lemba Harau waterfalls. Rock-climbers negotiate careful routes up the cliffs, while walking trails meander through emerald-green rice paddies to the valley's quicksilver cascades. Comfortable homestay accommodation in the architectural style of West Sumatra's Minangkabau people sits amid cooling lotus ponds. Transport and accommodation for the Harau Valley can be arranged with Lite 'N' Easy Tour in Bukittinggi.

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