The Dong Phayayen Forest is a UNESCO World Heritage Site located in Thailand. It is part of the larger Dong Phayayen-Khao Yai Forest Complex, which spans over 2,000 square kilometers. This forest is known for its rich biodiversity, including various species of flora and fauna, some of which are endangered. The forest is home to several wildlife species, such as the Asian elephant and the Indochinese tiger. It also features a range of ecosystems, from tropical rainforests to dry deciduous forests. The area is important for conservation efforts and provides opportunities for eco-tourism and research.