Northern Laos

At this long-running ecotourism project, a series of ziplines criss-cross the canopy in the Nam Kan NPA – home to clouded leopards, black bears and the black-crested gibbon – giving you the chance to soar across valleys and stay in 40m-high tree houses, claimed to be the world's tallest. There are three tour options (two-day Express, or three-day Classic and Waterfall), each involving a serious trek. Well-cooked meals are ziplined in by your guide.

Luang Namtha–Huay Xai or Ban Na Lae–Huay Xai longboat (one day) You can now only take the boat as far as Ban Phaeng, where a dam has recently been built; from here you are picked up and driven the remaining route to Huay Xai. What was a two-day experience is now just a day, though you still have around eight hours of puttering downriver. The journey starts in Luang Namtha where you are driven by car to Ban Na Lae to board the boat.

Hat Sa–Muang Khua is no longer possible since the Nam Ou (Ou River) was dammed, although Muang Khua–Nong Khiaw (six hours) still sees boats leave Muang Khua every morning, passing through Muang Ngoi Neua (five hours) before arriving in Nong Khiaw, and taking you through the country's most spectacular karst scenery. However, it is necessary to change boats to pass a large dam about one hour north of Muang Ngoi Neua.

Nong Khiaw–Luang Prabang (one day) Due to the damming of the Nam Ou, the boat trip to Luang Prabang was not possible at the time of research but, like the other dam-affected river trips, it may be available in sections in the future, and will involve hopping in and out of vehicles and boats to accommodate the obstacles. Otherwise, it is possible to sign up for kayaking trips in Luang Prabang and Nong Khiaw that include short but beautiful sections of the river.

As you approach Phongsali (ພົງສາລີ) via a sinuous mountain road, the town rears up suddenly on a ridgetop plateau. Often wrapped in mist, its atmospheric wooden Yunnanese shophouses and other buildings, spanning biscuit-brown to powder-blue, shelter below the peak of Phu Fa ('Sky Mountain'; 1625m) rising majestically in the background. The location gives the town panoramic views and a refreshing climate that can swing from pleasantly warm to downright cold in a matter of hours – expect icicles in the cold season and bring a jacket and waterproofs just in case, even in April.

The town's population is a mix of Phu Noi and Haw/Yunnanese, both long-term residents and more recent immigrants. That said, no one comes to Phongsali to experience the town, which can feel unfriendly and very untypically Lao; it's the trekking in the surrounding hill country and its vivid population of ethnic peoples that justifies the considerable effort to get here.

Joining a truly fascinating 18-point tour is the only way to see Vieng Xai's seven most important war-shelter cave complexes, set in beautiful gardens backed by fabulous karst scenery. A local guide unlocks each site while an audio guide gives a wealth of first-hand background information and historical context. The Kaysone Phomvihane Cave still has its air-circulation pump in working order and is the most memorable of the caves.

Mysterious giant stone jars of unknown ancient origin are scattered over hundreds of hilly square kilometres around Phonsavan, giving the area the misleading name of Plain of Jars (ທົ່ງໄຫຫິນ). Remarkably, little is known about the Austro-Asiatic civilisation that created them, although archaeologists estimate they date from the Southeast Asian iron age (500 BC to AD 200) and were likely used for elaborate burial rituals.

Smaller jars have long since been carted off by collectors but around 2500 larger jars, jar fragments and 'lids' remain. As the region was carpet-bombed throughout the Indochina wars, it's miraculous that so many artefacts survived. Only nine of the 90 recorded jar sites have so far been cleared of unexploded ordnance (UXO), and then only within relatively limited areas. These sites, and their access paths, are delineated by easily missed red-and-white marker stones: remain vigilant.

Sites 1, 2 and 3 form the bases of most tour loops.