With its tallest peak reaching 1271m, Nam Nao National Park is easily visible among the undulating sandstone hills of the Phetchabun range. However, it remains a seldom-visited place, at least as far as tourists go, with plenty of wildlife and some good, challenging hikes.
At just under a thousand square kilometres, Nam Nao, which is 160km south of Loei by road, is home to a healthy wildlife population: around a hundred mammal species, including large animals such as forest elephant and banteng and a handful of tigers, and more-often-seen barking deer, gibbons and leaf monkeys, as well as over two hundred bird species. These creatures thrive in habitats ranging from tropical bamboo and banana stands to the dominant features of dry evergreen forest, grasslands, open forest and pine stands that look almost European.
Though the park was established in 1972, it remained a stronghold for guerillas of the Communist Party of Thailand until the early 1980s and was regarded as unsafe for visitors. Still much less visited than Phu Kradung, it can provide a sense of real solitude. The range of wildlife here also benefited from a physical isolation that stopped abruptly in 1975, when Highway 12 was cut through the park and poachers could gain access more easily. However, as the park adjoins the Phu Khieo Wildlife Sanctuary, there is beneficial movement by some species between the two areas.