Chitwan National Park is the oldest national park in Nepal. It is situated in the subtropical inner Terai lowlands of South-Central Nepal. And the park was designated as a World Heritage Site in 1984.
The Chitwan National park covers a pristine area with a unique ecosystem of significant value to the world. It contains the Churiya hills, ox-bow lakes, and flood plains of Rapti, Reu, and Narayani Rivers. So, approximately 70% of the park vegetation is sal forest. And the remaining vegetation types include grassland (20%), riverine forest (7%), and sal with Chirpine (3%). The latter occurring at the top of the Churiya range. The riverine forests consist mainly of Khair, sissoo, and simal.
The grasslands form a diverse and complex community with over 50 species. And the Saccharum species, often called elephant grass, can reach 8 m. in height. The shorter grasses such as Imperata are useful for thatch roofs.
In Chitwan National park, there are more than 43 species of mammals and over 450 species of birds. Similarly, there are more than 45 species of amphibians and reptiles in the park. And also within the park lie the Churia hills, ox-bow lakes, and the flood plains of Rapti, Reu, and Narayani Rivers. The Churia hills rise gradually towards the east from 150m to over 800m elevation. The lower but more rugged Someshwor hills occupy most of the western portion of the park.
The floodplains of Chitwan contain rich alluvial soils. The park boundaries have been delineated by the Narayani and Rapti Rivers in the north and west and the Reu River and Someshwor hills in the south and south-west. It shares its eastern border with the Parsa Wildlife Reserve.