When it's said that Mahabharata is the encyclopedia of Indian cultural history, it's not really an exaggeration and some of the findings really leave you surprised. In Sabha Parva of Mahabharata, Chapter 21, there are two verses on Naga worship at the old capital of Magadha.

The Naga-s worshipped at the old capital of Magadha (Rajagriha) were: Arbuda, Shakravapin, Svastika, Mani-naga, Kaushika and Manimat. An inscription dated 1395 AD was discovered from Biharsharif which is near to Rajagriha mentioning the construction of a temple.

The temple was dedicated to the deity Kashuika-naga who was said to be worshipped in that region as per Mahabharata. Not only that, many old Naga sculptures have been excavated from the ruins of Rajagriha. The extent of cultural continuity is simply incredible.

Reference: p. 395-99, 'An Inscription from the Patna District' by D C Sircar, Vol. 29, The Indian Historical Quarterly, 1953.