By Mr. Phoenix - Hoang Anh Nguyen, Cat Ba Nomad · Last updated 24 August 2026 · Written on Cat Ba Island

There are fewer than 70 Cat Ba langurs left alive, and every single one of them lives on this island. Not in a reserve somewhere else, not in a zoo population that can be released later. Here, on the limestone cliffs you sail past on a day trip. It is one of the rarest primates on earth, and the story of how it survived is the most interesting thing about Cat Ba that almost no visitor hears.

A primate that exists on one island and nowhere else

The Cat Ba langur, also called the golden-headed langur, is endemic to Cat Ba Island. UNESCO lists it among the defining species of the Cat Ba Biosphere Reserve and describes it plainly as a primate "found nowhere else in the world". The IUCN classifies it as Critically Endangered, the last category before Extinct in the Wild.

Adults are dark charcoal with a bright cream-gold head and shoulders, which is where the English name comes from. Infants are born a startling orange and darken over their first year. They live in small groups on near-vertical limestone, feeding on leaves from cliff vegetation, and they sleep in caves and rock ledges rather than trees.

How it nearly ended

The collapse happened fast and it was not habitat loss. Between 1970 and 1986 an estimated 500 to 800 langurs were killed, hunted for use in traditional medicine. By 2003 the entire global population had fallen to roughly 40 individuals, split into groups so isolated that several contained no breeding females at all.

Forty animals, on one island, with some groups already reproductively dead. That was the low point, and it happened within living memory of people still working on Cat Ba today.

The turning point: November 2000

The Cat Ba Langur Conservation Project launched in November 2000, run jointly by Muenster Zoo and ZSCSP in partnership with Cat Ba National Park. The approach was unglamorous and it worked: ranger patrols were increased, hunting equipment was found and removed, caves and hunters trails were mapped and regulated, and Special Protection Zones were given fixed, enforced boundaries.

By the end of 2001, hunting of the Cat Ba langur had stopped. In 2006 the National Park boundary was expanded so that the entire remaining population sat inside protected territory. Roughly 40 percent of the langurs now live in a strictly protected sanctuary on the eastern peninsula of the island. A further three individuals are held at the Endangered Primate Rescue Center in Cuc Phuong National Park as an insurance population.

The number has roughly doubled since the low point. That is a genuine conservation success, and it is also still fewer than 70 animals, which is why the protection rules are strict and why they are worth respecting.

The numbers, at a glance

Can you actually see one? An honest answer

Probably not, and we would rather tell you that before you book than after. The core of the population lives inside a strict protection zone that is closed to tourism, on cliffs that are difficult to approach even for rangers. Anyone guaranteeing you a langur sighting is either confusing them with the macaques on Monkey Island, which are a completely different and very common species, or is simply selling you something.

What is realistic: on a quiet morning boat trip through the north-eastern channels of Lan Ha Bay, with binoculars and a guide who knows which cliff faces the groups use, you have a small but real chance of spotting movement high on the rock. Most of our guests never see one. The ones who do talk about it for years.

The more reliable way to meet the species is on foot in Cat Ba National Park, not because langurs are there in the open, but because the forest, the karst and the ranger stations make the scale of the protection effort concrete in a way a boat deck does not.

The rules we follow, and ask you to follow

• No approach. Boats keep their distance from known cliff groups. We do not manoeuvre closer for a photo.
• No noise. Engines idle down and speakers go off in the sensitive channels. Sound carries extraordinarily well off limestone.
• No feeding, ever. This applies to the macaques on Monkey Island too. Fed primates become aggressive primates, and then they become a management problem.
• No drones near cliff faces. They are read as aerial predators and cause groups to abandon feeding sites.
• Report, do not chase. If a guest spots a group, we log location and time and pass it to park staff. Observation data is genuinely useful.

If a tour operator offers to get you close to the langurs, that is not an advantage. That is the behaviour that nearly finished the species.

The wider picture: why Cat Ba is protected twice over

The langur is the headline species but not the whole story. Cat Ba was designated a UNESCO Biosphere Reserve in 2004, covering 26,419 hectares, of which 16,417 hectares are terrestrial and 10,002 hectares marine. Surveys within the reserve have recorded 2,026 species, including 741 plants, 119 fish, 160 corals and 23 mangrove types.

In 2023 UNESCO went further and inscribed Ha Long Bay and the Cat Ba Archipelago together as a World Natural Heritage site under criteria vii and viii, an area of 65,650 hectares containing 1,133 islands and islets. The citation calls it the most extensive example of marine-invaded tower karst on the planet. The langur appears in that citation by name, listed as critically endangered and noted as sensitive to tourism disturbance.

That last phrase is the part the industry here needs to take seriously. Cat Ba is growing quickly as a destination. Whether the langur count keeps climbing depends in large part on how the boats behave.

What it costs to get near langur country

You cannot buy a ticket to see a langur, but you can buy a ticket into the habitat that protects them, and those fees are what pays for ranger patrols. These are the current rates, set by route rather than as one flat price, which is why you will see three different numbers quoted across the internet.

Children under six and visitors with severe disabilities enter free. Seniors, students and people from recognised ethnic minority groups pay half, with documentation. Fees are revised periodically, so treat these as planning figures and confirm at the window.

The park the langurs live in, by the numbers

Cat Ba National Park was established in 1986 and covers around 152 square kilometres of the island. It sits roughly 14 kilometres north east of Cat Ba Town and 9.4 kilometres south west of the Gia Luan ferry terminal. Surveys inside the park have recorded 741 plant species and 282 animal species, and the park boundary was redrawn in 2006 specifically so that every remaining langur fell inside protected territory.

The trail network is longer than most visitors realise. Ngu Lam Peak is the short option at around two hours. Ao Ech to Viet Hai runs four to six hours. May Bau to Hospital Cave is about four hours, and Kim Giao to Me Con to Tung Di is roughly five. None of these routes enter the strict protection zones where the langurs live, which is the point.

Frequently asked

Planning your trip? Start with how to get here from Hanoi, then read what there is to do on the island.