Khao Yaii National Park, northeast of Saraburi and some 200 kilometres from Bangkok, covers parts of four provinces at an average elevation of 800 metres.

Khao Yai is some 540,000 acres in area, has a highest peak of 1,351 metres and contains within its rain forests and high grasslands numerous species of protected wildlife, such as deer, bears, tigers, elephants, giant hornbills, sunbirds and silver pheasants. The park is laced with hiking trails, and has 10 rapids and waterfalls.