Nam Nao National Park

Nam Nao National Park covers roughly 966 square kilometres of highland plateau straddling Phetchabun and Chaiyaphum provinces, most of it above 800 metres — cool enough that December-January nights can drop close to 0°C in cold years. Entry is 200 THB for foreign adults (100 THB for children), 40/20 THB for Thai nationals, open daily 06:00-22:00.

The elevation changes the forest completely: instead of the tropical jungle typical further south, Nam Nao mixes dry dipterocarp and hill-evergreen forest with pine stands and open grassland, plus stretches of dense bamboo. Highway 12, the Lom Sak-Chum Phae road, cuts straight through the park — the Phu Kho viewpoint at kilometre 46 is the standout stop, looking out over pine-covered ridgelines and popular at sunrise when mist pools in the valleys. Underground, Tham Yai is one of the longest known cave systems in Thailand: 9,817 metres of passage dropping 76 metres through five entrances, lined with stalactites and stalagmites. The full system is a serious caving undertaking, not a casual walk-in — check with park rangers before going beyond the entrance chambers.

Wildlife here includes elephants, gaur, banteng, sambar and barking deer, Asian black bears, sun bears, and golden jackals, drawing more serious wildlife-watchers than the average day-tripper. Elephants regularly cross Highway 12 itself, especially at dusk and into the evening, and the park department issues periodic warnings to drivers to slow down through the forest sections — a 2026 dispute over widening the highway has centred on exactly this wildlife corridor.

Watch out: Roads and trails get slick fast in the rainy season (June-October), and the cool season (November-February) can catch visitors off guard — pack a jacket for early mornings and after dark, unusual advice for Thailand but necessary here.

Insider Tip: Drive Highway 12 at reduced speed around dawn and dusk, even outside official elephant-crossing alerts — the forest comes right up to the tarmac on both sides.