Phu Soi Dao National Park

Phu Soi Dao National Park is a protected mountainous national park on the Thai-Laos border in Chat Trakan District, Phitsanulok Province, also extending into Uttaradit Province. Established in 2008 as Thailand's 109th national park, it covers about 340 sq km of pine forests and high mountains. It is notable for Phu Soi Dao peak (2,102 m), the vast Lan Son pine meadow, seasonal fields of Utricularia flowers, and waterfalls such as Sai Thip and Phu Soi Dao.

Visitors can expect a remote, forested mountain park with a visitor centre and headquarters area at lower elevation and a strenuous 6.5 km uphill trail to the summit plateau. The plateau features Lan Son, an open pine meadow with camping grounds, viewpoints along the border, seasonal purple Utricularia (Dok Ngon Nak) fields, and nearby waterfalls. Facilities are basic, especially on the summit where visitors must camp and carry supplies.