Arun valley trekking trail lies in Makalu – Barun National park connects Mt. Makalu region & Mt. Everest region by crossing Salpa pass 3350 m. The trekking route offers beautiful views of mountains such as, Mera Peak, Mt. Everest, Mt Makalu, Mt. Cho-Oyu etc, Salpa Lake 3414 m, waterfalls and ethnic Sherpa villages. It is non touristic region but have many opportunities of Natural & Cultural diversity. The trekking route can be extend to Sherpani col and west col into Upper Hongu valley but this route is more technical as compare with other trekking, the normal route head Salpa pass to Lower Khumbu region so there will be another chance to extend Kalapatter & Everest Base camp after Puiyan.