Odantapuri (also called Odantapura or Uddandapura) was a prominent Buddhist Mahavihara in what is now Bihar, India. It is believed to have been established by Gopala I in the 8th century. It is considered the second oldest of India's Mahaviharas after Nalanda and was situated in Magadha. The vihara perished at the hands of Muhammad bin Bakhtiyar Khalji, a Turko-Muslim invader in late 1100s, when he launched multiple raids on Bihar and adjoining territories.