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 Sun Koshi. Rafters either drive back Chatara via Biratnagar or fly from Biratnagar to Kathmandu.