Khao Yai National Park (Thai เขาใหญ่) is a national park in Thailand. It lies largely in Nakhon Ratchasima Province (Khorat), but also includes parts of Saraburi, Prachinburi and Nakhon Nayok provinces. It was the country's first national park, established on September 18, 1962. A major role in its establishment was done by Boonsong Lekakul, one of the 20th century's most famous conservationists in Thailand.

The park is the second largest in Thailand. It covers an area of 2,168 square kilometers, including evergreen forests and grasslands. Its altitude mostly ranges from 400 to 1000 m above sea level. There are 3,000 species of plants, 320 species of birds and 67 species of mammals, including Asiatic black bears, Asian elephants, gaur, tigers, gibbons, Indian sambar deer, Indian muntjac, dholes, and wild pigs. Its waterfalls include the 80 metre Haew Narok. Namtok Sarika is popular with the Thais.

Recent wildlife studies show that animal ranges, particularly the few resident tigers, are impacted by human activity near the center of the park. This study has not impacted the government's call for private lodging concessions within the park itself.

The park is often visited by travellers from Isan, Bangkok and beyond, for whom there are over 50km of hiking trails.

In 1984 the park was made an ASEAN Heritage Site, and on July 14 2005 the park together with other parks in the Dong Phaya Yen mountains was inscribed as a UNESCO World Heritage Site under the name Dong Phaya Yen–Khao Yai Forest Complex. Lands adjacent to the national park are increasingly developed into luxury hotels and golf courses for weekending visitors from Bangkok. Such development limits wildlife corridors and permanently reduces future conservation and land acquisition ability.

The fee is 200 baht for foreigners, and 20 for Thais. Food is available from private concessions within the park. As well, night-time "wildlife spotlighting" is available via pick-up trucks in the early evening. Animals sighted usually are limited to deer and civet cats, and only rarely include elephants.

Extracted from Wikipedia: Khao Yai National Park