Phu Hin Rong Kla was the former strategic headquarters of the Communist Party of Thailand (CPT). Today it's a national park covering about 307 sq km of rugged mountains and forest, much of it covered by rocks and wildflowers. The elevation at park headquarters is about 1000m, so the area is refreshingly cool even in the hot season. The main attractions aren't too far from the main road through the park and include the remains of the CPT stronghold and the administration building.
The remains of the CPT stronghold include a rustic meeting hall and the school of political and military tactics. The buildings in the park are made out of wood and bamboo and have no plumbing or electricity – a testament to how primitive the living conditions were.
There is a modest museum at the park headquarters that displays a few battered relics from the CPT days, although there’s little English explanation. At the end of the road into the park is a small White Hmong village.
If you’re not interested in the modern history of Phu Hin Rong Kla, there are waterfalls, hiking trails and scenic views, as well as some interesting rock formations – jutting boulders called Lan Hin Pum and an area of deep rocky crevices where People’s Liberation Army of Thailand (PLAT) troops would hide during air raids, called Lan Hin Taek. Ask at the visitor centre for maps.
Phu Hin Rong Kla can become quite crowded on weekends and holidays; for a more peaceful experience try to visit midweek.