Spend the night in the jungle, then rise well before dawn to spend time with semi-habituated northern buff-cheeked gibbons at this community-based ecotourism project (CBET) set up by Conservation International (CI; www.conservation.org) just outside the border of Virachey National Park, north of Veun Sai. The high-season-only tours cost US$100 to US$200 per person for a one-night/two-day tour, depending on group size and which tour company you choose. Most companies in Ban Lung can arrange these trips on behalf of CI.

This species was only discovered in 2010 and the population here is believed to be one of the largest in the world at about 500 groups. Hearing their haunting dawn call and seeing them swing through the canopy is memorable. These tours also offer the opportunity to experience dense jungle, open savannah, rivers and waterfalls, and to visit Kavet and Lao villages.

CI has an exclusive arrangement with the village near the gibbon site to run these tours within the Veun Sai–Siem Pang Conservation Area (VSSPCA). You stay at least one night in the jungle sleeping in hammocks or in a community-based homestay. The fee includes entrance to the VSSPCA, guide, homestays and camps, and all meals. The gibbon-viewing season runs from November to mid-June – it's too wet at other times – and the visits are limited to six people at a time. For an organised tour to the area with transportation, try Gibbon Spotting Cambodia.