The equatorial island is the third largest in the world and is divide among the countries of Brunei, Malaysia and Indonesia which holds about 73% of the total land. One of the oldest rainforests in the world is found here along with a significant cave system and a mangrove forest. Asia’s largest cave and biggest flower are both found in Borneo.

Mount Kinabalu and Kinabalu Park

Mount Kinabalu

It’s the highest mountain in the Malay Archipelago and the world’s 29th most prominent mountain, but it’s the ecosystems that surround the mountain that the most remarkable. The Kinabalu montane alpine meadows and other ecoregions that surround the mountain are home to nearly 6000 species of plants, more than 300 bird species and over 100 types of mammals. This is one of the richest biological sites in the world and is also host to the giant Rafflesia plants and the Borneo orangutan.

Rafflesia has the largest flower on the planet, spreading over 100 cm in diameter and weighing around 10 kg. The flower is the only part of the plant that’s visible and uses its scent (described as smelling like rotting flesh) to attract insects. The Rafflesia compete with other insectivorous pitcher plants for nourishment, but higher up the slopes is found the richest variety of orchids in the world.

Maliau Basin Conservation Area

Maliau Basin

If you’ve ever wondered what the earth looked like when dinosaurs walked the planet, it was probably much like the Miliau Basin. It’s a fair distance from any inhabited regions and has remained untouched due to the difficulty in reaching the area. A 1700 m escarpment borders the basin, further discouraging visitors. The 390 sq km inside the nearly circular water catchment is composed of pristine forest with a single river that drains the area. Often called “Sabah’s Lost World”, the basin is a protected area and awaiting World Heritage status.

The only way to see the basin is by taking an official tour offered by a single company. The five-day itinerary includes long, strenuous hikes through isolated forest. Visitors must have a doctor’s note to verify their fitness and are required to purchase helicopter evacuation insurance in the event they are injured.

Kakaban Island

Kakaban Island

A 1,913 acre island in the Derawan Island chain, Kakaban is covered in limestone cliffs and dense jungle that reaches down to the water. Despite the beauty, this isn’t what makes the island amazing; it’s the mangrove-encircled lake in the middle of the island. The water is brackish and slightly above sea level, protect from the sea by the island. “Kakaban” translates to “hug” as the island hugs the lake in it’s centre.

Inside the lake live thousands of stingless jellyfish, creating a paradise for diving. The four species of jellyfish are very different in appearance and do have toxins, but none that affect humans. Several other salt water creatures live here including sea anemones and tunicates.

Blue Light Cave is a another point of interest on the island, descending 21 metres down a narrow chimney before opening into a large cavern with a view of the sea.

Maratua Island

Maratua Island

Also in the Derawan Archipelago and with a pond full of stingless jellyfish, Maratua is a beautiful curved island covered with trees and steep cliffs. The beaches of white sand are very popular with tourists, but the prepared visitor arrives with a snorkel or scuba gear. Maratua curves around an enormous lagoon filled with the third highest level of marine biodiversity on the planet. Several coral reefs around the island are home to brightly coloured fish, manta rays and other marine life. Sea turtles visit the island and there are nesting grounds in several places in the area.

One section of sea near the island is popular with green sea turtles, and hundreds of them can be seen gliding through the waters in search of food. Divers and boaters have the chance to experience swimming with some of the oldest animals in the sea.

Danau Sentarum National Park

Danau Sentarum

In the heart of Borneo sits the most biodiverse lake system in the world. Upstream from the Kapuas River Delta, the flood plain contains some 20 seasonal lakes along with peat forest and a freshwater swamp. The park surrounds most of the flood plain and consists of mainly lake and swamp. In addition to a great number of fish species, the park is home to the proboscis monkey, orangutans and 26 reptile species. Of all the mammal species found in Indonesia, 29% are in Lake Sentarum Park.