Sankhuwasabha संखुवासभा

Sankhuwasabha is a large, mountainous district in north-eastern Koshi Province, its territory running from subtropical Arun valley floor up to the glaciers below Makalu — at 8,485 metres the world's fifth-highest peak — and the surrounding Makalu Barun National Park, one of the most biologically diverse protected areas in Asia. The trailhead town of Num, reached by jeep from Khandbari, is the standard entry point for the long Makalu Base Camp trek, which climbs from the lush Barun valley through alpine meadows to the 5,000-metre base. The Upper Arun Valley trek offers a lower, somewhat shorter alternative that links the Arun River corridor to the Khumbu.

The district is quieter and considerably less crowded than the Everest circuits to its west — most trekking parties number in single digits. Khandbari, the headquarters, is a pleasant mid-hill town, and the area around Tumlingtar on the Arun valley floor is subtropical and warm even in winter. The Arun River itself, one of the world's oldest river systems, flows south from Tibet directly through the district, giving access to a rare gradient of ecosystems in a single walk. October to May is the trekking window; guides and permits for Makalu Barun are mandatory.