Sunsari Districtसुनसरी जिल्ला

Sunsari packs 926,962 people into 1,257 km² of eastern Tarai, making it the most densely populated district in Koshi Province (737/km²). The quiet plains town of Inaruwa is the headquarters, but the district's real engines are its two sub-metropolitan cities — the only two in the province: Itahari, the booming highway junction, and Dharan, the historic market where the hills meet the plains. Carved out of greater Morang in the 1962 reorganisation, Sunsari has grown 1.86% a year since 2011 as migration from the hills continues.

Dharan, established as a municipality in 1958, embodies the district's hill-plain character: a trading post where hill villagers traditionally descended to the Tarai, it later hosted a British Gurkha camp (established around 1960, wound down in the 1990s) that tied the town to the British Army's eastern recruitment, and its population today is strongly Kirat — Rai and Limbu together over 30%, with the Kirat religion professed by 35% of residents. To the district's west, along the Koshi river, lies Koshi Tappu Wildlife Reserve, established in 1976 and designated Nepal's first Ramsar site in 1987 — 175 km² of floodplain grassland and wetland that shelters the country's last wild water buffalo (arna) alongside Gangetic dolphins and hundreds of bird species.

The district also holds Barahachhetra, one of Nepal's most venerated Vishnu pilgrimage sites, at the point where the Koshi leaves its mountain gorge — the municipality around it carries the shrine's name. Industry lines the Biratnagar–Itahari–Dharan corridor through Duhabi, knitting Sunsari and Morang into eastern Nepal's largest urban-industrial cluster.