Dong Phaya Yen Mountains

Dong Phaya Yen or Dong Phya Yen is a mountain range in Thailand. The Dong Phaya Yen Mountains consist mainly of a range of medium-height hills stretching southwards of the Phetchabun mountains in an arch until reaching the northern side of the Sankamphaeng Range. The mountain chain has a length of about 170 km and reaches a maximum altitude of 900 m above sea level at Khao Phang Yai.

Dong Phaya Yen was once known as Dong Phaya Fai or "Jungle of the Fire Lord" because this area was once a vast forest. It was not possible to use a cart across the forest and travel had to be on foot. Malaria and other illnesses killed most travelers who dared to pass through the woods. Much of the forest cover, however, was destroyed since the beginning of 20th century when the railway line and roads were built connecting Central Thailand and Isaan.

Protected areas
The protected areas located in the Dong Phaya Yen mountains are Pa Hin Ngam National Park, Sai Thong National Park, Tat Ton National Park, Nam Phong National Park, Phu Lan Ka National Park, Sap Langka Wildlife Sanctuary and the Khao Somphot Non-hunting Area.

These mountains, together with the Sankamphaeng Range, form the Dong Phayayen - Khao Yai Forest Complex, which includes several national parks. This area was inscribed on the UNESCO World Heritage List. Altogether 6155 km² are protected in the complex.