Phu Wiang National Park (PWNP) is in Khon Kaen Province, northeastern Thailand, covering the area of the Phu Wiang Mountains. It is best known for its numerous dinosaur bone paleontological sites, The park is one of the world's largest dinosaur graveyards. In 1996, the remains of Siamotyrannus isanensis, a new family of carnivorous thunder lizards, were unearthed in the park.