Gunung Mulu National Park: Caves, the Pinnacles Trek, and How to Get There

Gunung Mulu National Park in northern Sarawak protects some of the largest cave passages on Earth, a 2.4-million-year-old karst landscape, and primary rainforest that earned UNESCO World Heritage status in 2000 for all four natural criteria — one of very few places anywhere to manage that. It is also one of the most logistically unusual parks in Malaysia: there is no road in, everything is booked through the park itself, and the daily rhythm revolves around a bat exodus. Here is how a Mulu trip actually works as of 2026.

The Show Caves

Four caves are open on guided tours, sold in two pairings from park HQ.

Deer Cave and Lang Cave (afternoon tour, approximately RM35 as of 2026) are a 3 km walk from HQ on a flat boardwalk through the forest. Deer Cave is the headliner — a passage so large that the guides’ usual comparison is fitting several jumbo jets inside, with a ceiling over 120 m high in places and a colony of an estimated 2–3 million wrinkle-lipped bats. Lang Cave next door is small but has the park’s best stalactite and stalagmite formations.

Wind Cave and Clearwater Cave (morning tour, approximately RM65–70 including the boat) are reached by longboat up the Melinau River, usually with a stop at a Penan market. Clearwater is part of one of the longest surveyed cave systems in the world — well over 200 km of mapped passage — and the swimming spot in the cool spring at its mouth is the standard post-tour reward. Bring swimwear.

The Bat Exodus

On dry evenings between roughly 5pm and 6.30pm, the Deer Cave colony spirals out of the entrance in long smoke-like ribbons to hunt — by some estimates consuming several tonnes of insects a night. The park has a purpose-built observatory with benches near the cave mouth. It is free once you have paid park entry, and it is genuinely one of Borneo’s great wildlife spectacles. The bats stay home in heavy rain, so build in more than one evening if the exodus matters to you.

The Pinnacles Trek

The park’s signature challenge is a 3D2N guided trek to a viewpoint over the Pinnacles — a forest of razor-edged limestone blades up to 45 m tall on the flank of Gunung Api.

• Day 1: longboat upriver, then an 8–9 km flat walk to Camp 5 beside the Melinau River.
• Day 2: the climb — only 2.4 km, but gaining roughly 1,200 m, with the final third on ropes, rungs and about 15 aluminium ladders bolted to the rock. Most groups need 8–11 hours up and back. Guides enforce cut-off times at checkpoints and will turn back anyone too slow to descend safely in daylight.
• Day 3: walk and boat back out.

Book through park HQ or mulupark.com; expect approximately RM450–650 per person as of 2026 depending on group size, covering the compulsory guide, Camp 5 accommodation and boats, but not food (you carry your own). This is a serious, knee-punishing scramble — fit hikers love it, unprepared ones get turned around.

Park Fees and Booking

Park entry is approximately RM30 for foreign adults as of 2026, valid for five days, with discounts for Malaysians and children. Every cave tour, trek and adventure-caving trip is booked separately through the park office or mulupark.com. In July and August, book show caves a few days ahead and the Pinnacles weeks to months ahead — guide and Camp 5 capacity is limited. Verify current fees on mulupark.com before you travel.

Where to Stay

• Park HQ accommodation — the practical choice, inside the gate next to the trailheads. Hostel beds from approximately RM65 and en-suite longhouse or bungalow rooms from approximately RM250–400 as of 2026, booked via mulupark.com. There is a decent café at HQ.
• Mulu Marriott Resort & Spa — the only resort, about ten minutes away by road with a shuttle. Longhouse-style rooms over the forest, a pool, and rates of approximately RM450–750 per night as of 2026.
• A handful of family-run guesthouses sit across the river from HQ at backpacker prices.

Getting There

There is no road to Mulu — access is by air or a very long multi-day boat journey nobody practical attempts. MASwings (now under Sarawak state ownership) flies ATR turboprops from Miri in around 30 minutes, typically RM150–300 one way as of 2026, plus direct services from Kuching and Kota Kinabalu on selected days. Schedules shift, so check current routes when booking. Flights cancel in bad weather often enough that you should not book Mulu the day before an international connection. See our Miri guide for what to do on either side of the flight, and our Borneo itinerary for slotting Mulu into a longer trip.

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When to Go

Mulu is rainforest — it rains year round, and the park stays open year round. The relatively drier window of March to September gives you the best odds of the bat exodus flying and the Pinnacles trail being safe; the north-east monsoon from November to February brings the heaviest rain and occasional flight disruption. Humidity sits near 100% whenever you come, so pack accordingly.