Balirajgarh is an archeological site located at Babubarhi block in madhubani district 35 km from district headquarter. It is said to be the possible site of Ancient Mithila University. In 1938 Archeological Survey of India declared the site of national importance under the Ancient Monuments Preservation Act of 1904. Excavation has been done here in five phases from 1962 to 2014. The size of the bricks found in the wall are generally 1feet×1.5feet×4inch. During excavation antiquities of five phases of cultural periods, namely Northern Black soil, Sunga, Kushan,Gupta and later Pala period were discovered. According to regional legend, this was the capital of mythological asura King Bali. He was popular for his donations to the poor, Brahmins, scholars,and all those who came to his kingdom in expectation of financial help. According to some scholars, the fort was built by the last King of the Janaka Dynasty in Mithila.