Sun Koshi river is a river of Gold. It is one of the top ten rivers of the world for white water rafting. It is one of the most enjoyable river in the world. Sun Koshi is a watershed for most of Eastern Nepal and flows through valleys in Mahabharat range. The river flows towards east through Mahabharat range. The river gains strength from many glaciers fed tributaries on its way. This is a large volume river where most of the major rapids are formed by Monsoon debris brought in by side streams, and loose rock fall. Hence these rapids change from year to year.
The lower section of the river is a large volume river and is usually flat. The surroundings are heavily forested. The trip provides opportunity to look for 250 different species of orchids and River chats, dippers, flycatcher, tibias, wall creepers, bulbuls, fork tales, ibis bills are a few of the almost 400 species of birds available around the basin. There is a famous Hindu Pilgrimage known as Barah Chhetra near Tribenighat.

The rafting put-in point is Dolalghat, a three hours drive from kathmandu, and put-out point is at Chatara. Chatara is well connected by high ways. The estimated distance between these two points are 272 Km. Everyday 5 hours paddling on the river except first & last day make 7 days on the river. There are no roads and towns between put-in and put-out points. There are only picturesque villages, friendly people and a few places to stock up on beers and cigarettes. All along the river are beautiful white sandy beaches for camping.

Sun Koshi starts off fairly relaxed, with small class two rapids & small class three rapids to warm up on during the 1st couple of days. The rapids of grade 5 are countered in later days.