Tasek Merimbun

Tasek Merimbun is a shallow, tannin-stained blackwater lake covering approximately 7,800 hectares in the Tutong district, surrounded by peat swamp forest and the distinctive scrubland known as kerangas that defines much of Borneo's interior and creates a landscape unlike anything found in the coastal and lowland areas that most visitors to Brunei see.

The lake is fed by several small rivers and seasonal streams and is ringed by a mosaic of freshwater swamp forest, kerangas heath forest, and abandoned shifting cultivation areas — a patchwork habitat that creates one of the most ecologically diverse landscapes in Brunei.

UNESCO inscribed the site on its Tentative List as Tasek Merimbun Heritage Park, recognising its biodiversity value as a habitat for the Proboscis monkey (Nasalis larvatus), gibbon, Asian elephant (rare), estuarine crocodile (Crocodylus porosus) and over 200 species of birds including the globally threatened Chinese egret and Nordmann's greenshank.

The name Merimbun derives from the Malay word for 'lake' and the site is culturally significant to the local Tutong indigenous community, who have used the lake for fishing, collecting freshwater prawns and as a source of water for agriculture for generations, creating a cultural landscape that is inseparable from the ecological one.

Access requires a 4WD vehicle in the wet season; a rough dirt track leads from Tutong town to a basic wooden jetty where small boats can be hired to cross to the far shore, where a viewing tower provides panoramic views of the lake and surrounding forest canopy.

The Brunei government has designated the lake as a proposed heritage park under the Forests Act and a management plan has been under development since 2019, but visitor infrastructure remains minimal — there are no marked trails, no visitor centre and no formal interpretive signs, making the experience genuinely wild.

Saltwater crocodiles are present in the lake and are managed by the Wildlife Department; warning signs are posted at the jetty and local boatmen are trained in safe behaviour; the risk is real but managed, and attacks on humans are extremely rare.

For visitors seeking a genuinely remote experience in Brunei — far from the mosques, oil infrastructure and shopping malls of the capital — Merimbun is one of the few places that delivers authentic wilderness, and the combination of blackwater lake, peat swamp forest, Proboscis monkeys, and the chance to observe estuarine crocodiles from a safe distance makes the logistical effort of reaching it entirely worthwhile.

It is Brunei's largest natural lake and one of the most important wetland habitats in Borneo, home to species including the Proboscis monkey, gibbon, estuarine crocodile and over 200 bird species, many of them globally threatened.

The UNESCO Tentative List inscription signals international recognition of its ecological and cultural value, even if the protected area management plan is still being developed.

For visitors who want to experience Borneo's interior wilderness — the peat swamp and kerangas forest that once covered much of the island — Merimbun is the most accessible major site in Brunei.