Kishanganj is a town and district headquarters of Kishanganj district in Purnea division of Bihar state. Nestled in the foothill of Himalaya this border district historically has been part of Nepal and Sikkim. Kishanganj old name is Nepalgarh. In 1840 Kishanganj became part of main land Indian subcontinent after the local ruler lost battle with Mughals.Subsequently it was absorbed in British empire. It is part of the chicken neck of Indian map. It is located at 26°04′46″N 87°56′14″E . Main rivers of this district are Mechi, Mahananda, Kankai. it is the only tea producing district in Bihar.