The most accessible of Khammouane province’s three NBCAs is the Phou Hin Poun NBCA, more popularly known as the Khammouane Limestone NBCA and home to a dizzying array of wildlife, including elephants, tigers and macaques. Unlike the neighbouring Nakai-Nam Theun and Hin Nam No NBCAs to the east, the Khammouane Limestone NBCA can be accessed by road or river from a number of approaches, making it the most practical and affordable of the three to visit.
The best way to experience the park is on one of the organized tours that operate out of Thakhek or Vientiane, and that generally include kayaking, hiking and village stays. Although it will not allow you to penetrate the interior of the park to the degree a professionally organized expedition can, a do-it-yourself tour from Thakhek is also easily arranged and affordable.
The chief highlight of many of the tours is the journey by kayak through the wonderfully dramatic Tham Lot Kong Lo Cave, a natural 7km river tunnel through a limestone karst mountain into a hidden valley. Bring a torch (flashlight) and some rubber flip-flops as it can be necessary to wade through the more shallow stretches of the river. Green Discovery (t021/264680, www.greendiscoverylaos.com), which may have opened a new Thakhek office on the town square by the time you read this offers a three-day kayaking, cycling and trekking tour to the cave.
There’s an eco-resort within the park, the L’Auberge Sala Hine Boun (t020/755220, wwww.salalao.com; 120,500–200,000K), on the banks of the Nam Hin Poun River; it’s reached by taking a tuk-tuk from Na Hin (on Route 8) to Ban Na Phouak on the northern boundary of the NBCA, and then a boat up the Nam Hin Poun ($15; 2hr). The resort has comfortable bungalows and is within easy day-hiking distance of a number of hill-tribe villages, Tham Thieng cave and Tham Lot Kong Lo. Kayak excursions through the underground river can be arranged here but a cheaper option, especially if you’re travelling solo, is to arrive at the cave with your own transport and wait until you can split the cost of a boat and driver (around $10) with other sightseers.