Pang Sida National Park covers the area of Amphur Muang of Sa Kaew Province, Wattana Nakorn and Amphur Na Dee of Prachinburi Province. There are fertile forests consisting value natural resources and many beautiful natural uniqueness. Its area is about 594 km2. It was designated a national park on 22 February 1982 to be the 41st national park of Thailand.

Topography
The landscape is complex high mountains. It is fertile and composed of many kinds of plants. The forests include moist evergreen forest, dry evergreen forest, dipterocarp forest and grassland which are the important sources of water and streams. Wild animals found in the park, for examples, bull, elephant, red bull, tiger, deer, barking deer, bear, warthog, and hornbill. Tourists can easily see the wild animals living in the nature like Khao Yai National Park. There was also found white-water crocodiles in the year 1991 in the area of Huay Nam Yen Forest, Amphur Muang , Sa Kaeo Province. It was expected to be the biggest and the last living place for crocodiles in Thailand.

Climate
Most of the area is rain forest and in monsoon climate that causes rain regularly so that the temperature is not so hot. The rainy season starts from June to November. The winter is from December to February; approximately temperature is 8 – 15 degrees Celsius. The summer is from March to May.

Flora and Fauna
The forest in Pang Sida National Park is rain forest, semi-evergreen forest, montane forest and deciduous forest. There have valuable plants such as Yang, Krabak (a kind of Dipterocaparceae), Red Hopea, Makhaa mong, Tabak (a kind of Lagerstroemia), Sela (a kind of Lythreceae), Burmese ebony, hog plum, Samor (a kind of Terminalia) black wood and rosewood, each spreading in a forest of its kind, and lower plants such as rattan, fernmoss and many kinds of ground orchid.

Because the forest in this area is productive forest, and the source of many rivers, so that there is a good habitat for wild animals, every big and small size and more than 200 kinds of bird, found and spreading there, such as wild elephant, seladang, banteng, tiger, Asiatic black bear, hill myna and dove, and also rare fresh-water crocodile.