Kahalgaon, also called Colgong is a city and a municipality in Bhagalpur district in the state of Bihar, India, Close to the great Vikramshila University, that was famous as a centre of advanced learning across the world in the ancient times. Vikramasila University was one of the two most important centers of Buddhist learning in India, along with Nalanda University during the Pala dynasty.
In the vicinity of the town, now stands afirm the thermal power project from NTPC , known as "Kahalgaon Super Thermal Power Project".