Cat Tien National Park can be explored on foot, by mountain bike, by 4WD and also by boat along the Dong Nai River. There are 14 well-established hiking trails in the park, colour-coded by the level of difficulty and ranging from 2km to 26km in length. Some are flat and paved, while others are demanding, muddy slogs that require crossing streams. Only the three most difficult trails require the services of a guide, as well as transport to and from the start of the trail.

Be sure to book a guide in advance. They charge 800,000d for a day's trekking or birdwatching, regardless of group size. Take plenty of insect repellent and water. Leeches keep you company; 'leech socks' are provided by the guides. Boat trips start at 1,200,000d, plus 250,000d for a guide.

Feature: Wild Gibbon Trek

Golden-cheeked gibbons have been reintroduced into Cat Tien and this experience offers a rare insight into the lives of these charismatic primates. The trek (1,050,000d per person, maximum four people) runs daily from the park HQ and involves a 4.30am start to get out to the gibbons in time for their dawn chorus; you have a chance to watch two separate gibbon families go about their everyday business.

Golden-cheeked gibbons are very territorial, with dominant females, and live in nuclear family groups, with the young staying with their mother for up to eight years. As with most other endangered creatures in Vietnam, they're hunted for the illegal pet trade, with parents killed and babies taken away, and also for dubious traditional medicine purposes.

The trip includes a fully guided tour of the Dao Tien primate centre, typically done at 8.30am, straight after the trek. The wild gibbon trek is now run by the park authorities, with the support of Go East (www.go-east.org), and requires you to stay in park-run accommodation the night before, as river crossings in the dark are too dangerous. All proceeds go back into the national park and assist the rangers in their protection efforts. To avoid disappointment, book in advance through namcattien@yahoo.com.vn, or call ahead (0251-366 9228).