is made up of mountain ranges to the northwest of town about 1174 metres above mean sea level covered in the main by deciduous plants. Very cold during November-February, it once was the base from which communist insurgents conducted their struggles against the authorities during 1968-1982. Today it is accessible via two routes; off Highway No.12 (Phitsanulok-Lom Sak) at Ban Camp Son with a further distance of 30 kilometres of off highway No.21 at Ban Na Ngua, about 13 kilometres from town with a further distance of 30 kilometres. Both routes wind through considerably steep terrain. Interesting places include various viewing points, remains of communist bases and buildings, containing Holy Relic and the Si Dit waterfall.
- Rai B.N.
- Si Thep Historical Park