Tanahun District, a part of Gandaki Province, is one of the seventy-seven districts of Nepal. The district lies in central Nepal, with Damauli as it…Tanahun District, a part of Gandaki Province, is one of the seventy-seven districts of Nepal. The district lies in central Nepal, with Damauli as its district headquarters. It covers an area of 1,546 km² and has a population of 323,288. Previously the town of Bandipur was its district headquarter. The postal code of Tanahun is 33900.