Khao Yai National Park is an easy escape into the primordial jungle. The 2168-sq-km park, part of a Unesco World Heritage site, spans five forest types, from rainforest to monsoon. The park's centrepiece is Nam Tok Haew Suwat (น้ำตกเหวสุวัต), a 25m-high cascade that puts on a thundering show in the rainy season. Nam Tok Haew Narok (น้าตกเหวนรก) is its larger cousin, with three pooling tiers and a towering 150m drop.
Read more: http://www.lonelyplanet.com/thailand/nakhon-ratchasima-province/khao-yai-national-park/sights/parks-gardens/khao-yai-national-park#ixzz3sOEJPsWo