Into the Hidden River

9 Days on Nepal's Most Remote Rafting River

Days 1 to 2  |  Arrival and Kathmandu

Land at Tribhuvan International and spend two days in the Kathmandu Valley. Medieval woodcarved temples, UNESCO heritage sites, sacred stupas. Our team finalizes the river permits for the Arun sector while you explore the city. The cultural context matters here: you are about to enter one of the oldest river valleys in Nepal, and Kathmandu is the right place to begin.

Days 3 to 5  |  Into the Arun Valley

Fly from Kathmandu to Tumlingtar at 518 meters, where the air is warm and the Himalayan panorama above is visible on clear mornings. Trek to the put-in at Savaiya Khola through villages of the Rai and Limbu peoples, Tibeto-Burman communities whose presence in this valley predates any written record of Nepal. The river comes into view on the final stretch of the approach. Begin the descent and let the Arun set its own pace from the first day.

Days 6 to 7  |  The White Water

The Arun drops through the Mahabharat ranges in a series of sustained Class III and IV rapids, cutting through granite canyon walls and tectonic ridges that the river has been carving for tens of millions of years. The water is high-volume and cold, fed by glacial melt from the ranges above. Camp each night on riverside beaches where the nearest road is several hours away by foot.

Days 8 to 9  |  The Confluence and Return

The final rapids bring you to Barahkshetra, one of the most sacred Hindu pilgrimage sites in eastern Nepal, where the Arun meets the Sun Koshi and Tamur rivers. The take-out is at Chatara. Transfer to Biratnagar for the return flight to Kathmandu and your final night before international departure.

Day by Day

Days 1 to 2  Arrival and Kathmandu

Arrive at Tribhuvan International Airport and transfer to your hotel with a traditional Sherpa welcome. The Kathmandu Valley is the right beginning for a journey into one of Nepal's oldest inhabited river valleys. Day Two is a proper introduction to what Nepal holds before you leave the city behind. Pashupatinath Temple on the Bagmati River, the most sacred Hindu site in the country, where cremation ghats have operated on the riverbank for centuries. Boudhanath, the great stupa that anchors the Tibetan Buddhist community in Nepal. The Durbar Squares of Kathmandu and Patan, with their medieval Newari architecture, stone temples, and palace courtyards. The permits for the Arun sector are confirmed and the domestic flight to Tumlingtar is booked for the morning of Day Three.

Stay: Kathmandu Hotel

Days 3 to 5  Into the Arun Valley

Morning flight from Kathmandu to Tumlingtar, a small airstrip in eastern Nepal at 518 meters. The flight takes roughly 40 minutes and drops you into a different climate entirely: warmer, more humid, with the white wall of the eastern Himalaya visible to the north on clear mornings. From the airstrip, the journey transitions from aviation to foot. The trek to the put-in at Savaiya Khola passes through Rai and Limbu villages, communities of Tibeto-Burman heritage whose ancestors settled this valley long before the Kathmandu kingdoms existed. The houses, the agricultural terraces, the way the community is organized around the river rather than a road, all of it is a reminder that most of Nepal does not look like Thamel.

The Arun comes into view before you reach the put-in. It is a big river. Wide, brown-green, running with purpose from the north where it has already traveled hundreds of kilometers from its source near the Tibetan border. Safety briefing, gear check, and introductions to the full team before the first launch. The initial stretch introduces the character of the river: longer calm sections than the Trishuli, interspersed with rapid sequences that arrive with real force and require the full attention of every paddler. Camp on the first beach by late afternoon.

Stay: Tented Beach Camps

Days 6 to 7  The White Water Challenge

The Arun enters the Mahabharat ranges on this section and the landscape shifts completely. The valley narrows. The walls rise. The river, which has been moving through open country, is now cutting through ancient granite in a series of sustained Class III and IV rapids that represent the most technically demanding water on the entire run. The canyon walls on this section are some of the oldest exposed rock in the Himalayan system, forced upward by the collision of the Indian and Eurasian plates while the Arun continued to cut downward through them. Paddling through it is, in a very literal sense, moving through geological time.

The rapids here do not have the named individual character of the Kali Gandaki's Refund or the Trishuli's Upset. The Arun's challenge is sustained: rapid following rapid through a canyon where the echo of the water is the loudest sound in the world and the walls on either side are close enough to feel the cool air coming off the rock. Camps on this section are on narrow beaches tucked into bends in the canyon. The remoteness is total. No road, no trail, no settlement visible from the water. Just the river and the rock and the sky above the canyon rim.

Stay: Remote Riverside Camps

Days 8 to 9  The Confluence and Departure

The canyon opens on the final day and the character of the river changes as the Arun begins its approach to the confluence. Barahkshetra is one of the most significant Hindu pilgrimage sites in eastern Nepal, the point where the Arun, the Sun Koshi, and the Tamur rivers meet in a triple confluence that Hindus have considered sacred since before recorded history. The temple complex on the bank has been a destination for pilgrims from across the eastern hills for centuries. The rafts drift past it on the final stretch before the take-out at Chatara.

Pack the gear and transfer to Biratnagar, the commercial capital of eastern Nepal and the departure point for the return flight to Kathmandu. One final night in the city or direct transfer to Tribhuvan International Airport for international departure. Nine days. A flight into the eastern hills, a trek to a river that most visitors never reach, five days of Class III and IV water through one of the oldest canyon systems in the Himalaya, and a sacred confluence at the end of it.

Stay: Biratnagar Hotel or Kathmandu Hotel or International Departure

The Sherpa Standard

Every SherpaHolidays journey is fully supported. Here is what that covers for this trip.

Accommodation and Meals

• Kathmandu: Hotel accommodations on a bed and breakfast basis.
• River Camps: Tented beach camping throughout the rafting section with high-quality sleeping mats and full camp setup.
• River Meals: All meals during the expedition days: breakfast, riverside lunch, and dinner at camp, prepared fresh by the river kitchen team.
• Airport Welcome: Traditional welcome garlands and full expedition orientation on arrival in Kathmandu.

Leadership and Logistics

• River Lead: Certified English-speaking trip leader with expert knowledge of the Arun.
• Paddle Guides: Professional guides in every raft on all river sections.
• Safety Kayakers: Dedicated safety kayakers following every raft through Class III and IV water.
• Support Crew: Full team managing camp setup, gear maintenance, and equipment transfers.
• River Gear: International-standard self-bailing rafts, lifejackets, helmets, and dry bags.

Transport and Logistics

• Domestic Flights: Kathmandu to Tumlingtar and Biratnagar to Kathmandu, both included.
• Private Transfers: All overland travel in private air-conditioned vehicles.
• Permits and Fees: All river permits, national park entry fees, and sightseeing entrance fees covered.

What Is Not Included

• International airfare to and from Kathmandu
• Nepal entry visa fees
• Lunch and dinner while in Kathmandu
• Personal swimwear, river footwear, and medications
• Travel and emergency evacuation insurance. We can recommend providers.
• Tips for river guides, safety kayakers, and support crew

Five Things That Define This Trip

A River Older Than the Mountains

The Arun is one of the few rivers on earth that predates the mountain range it flows through. The Himalayan ranges rose around it rather than blocking it, leaving the Arun cutting through canyon walls that record 60 million years of tectonic collision. Paddling through the Mahabharat section means moving through geological time in a way that no other stretch of white water in Nepal offers.

Tibeto-Burman Villages Along the Bank

The Rai and Limbu communities of the Arun Valley are Tibeto-Burman peoples whose presence in this region predates the Kathmandu kingdoms. Their villages sit above the river on terraced hillsides with no tourist infrastructure, no guesthouses, no souvenir stalls. The rafts pass close enough to see the daily life on the banks, and the occasional villager who stops work to watch is watching something that arrived from outside rather than the other way around.

Sustained Class IV Through the Canyon

The Arun's character is different from the Trishuli or the Kali Gandaki. The challenge is sustained rather than concentrated: rapid following rapid through a narrow granite canyon where the walls rise close on both sides and the echo of the water makes conversation impossible. There are no famous named rapids on the Arun. There is just the river, continuous and serious, for the full length of the canyon section.

The Sacred Confluence at Barahkshetra

The Arun ends where it meets the Sun Koshi and Tamur rivers at Barahkshetra, a triple confluence that Hindus have considered one of the most sacred sites in eastern Nepal for centuries. The temple on the bank is a pilgrimage destination for communities across the eastern hills. The rafts drift past it on the final stretch before take-out. It is a quieter ending than most white water trips provide, and the right one for this river.

The Remoteness is Real

The Arun sees a fraction of the traffic that Nepal's more accessible rivers attract. Getting here requires a domestic flight and a trek rather than a drive from Kathmandu. The beaches on the canyon section have no road access. On the water, the nearest settlement is often several hours away by foot. This is not remoteness as a selling point. It is remoteness as a condition of the geography, and it produces a quality of silence and solitude that the more popular rivers cannot match.