River Arun (Grade 5) begins at Tumlingtar and ends at Chatara. Kartikeghat. The starting point can be approached either by flight or by road. A mini trek is required from both the airstrip or from the bus stop. Some parts of the river are smooth while some are rough and challenging.

On the sixth day Arun River meets Sunkoshi. The Arun provides come of the most challenging rafting in Nepal. And although the difficult access makes only three days on the river possible, the remote location and spectacular mountain views make this a real wilderness Rafters either drive back Chatrara via Biratnagar of fly from Biratnagar to Kathmandu.