Khao Yai National Park covers more than 2,000 square kilometers of forest and grassland in central Thailand. More than 50 km of hiking and biking trails wind through the long-standing nature preserve, and its many waterfalls include 150m-tall Haew Narok and 20m-tall Haew Suwat, immortalized in the Danny Boyle film The Beach. The park also shelters diverse wildlife such as bears, gibbons, elephants and hornbills. You can also see 2 million bats flying at Khao Luk Chang Bat Cave between 5pm to 6:30pm. Outside of the park, it's a bit Disneyland: you can visit farms, cowboy shows, italian or british villages, mazes, gardens, attraction parks, not really my thing. For food options, I recommend Pirom Cafe, Ribs Mann, Chocolate factory, and for accommodation Lala Mukha Tented Resort, Hobbit House (Baan Suan Noi) if you're fan of Lord of the rings, and the newest Sala Khao Yai and Myst Khao Yai.