It was during the times of Ajatasatru that the city of Pataliputra was built, and it was his grandson Udayin, who it is said shifted the capital from the hill fortress of Rajgir to the Water Fortress (jaldurga) of Pataliputra. As a result of the shift, the political importance of Rajgir declined gradually, but the religious importance remained and remains to this day. Rajgir had already become a desolate town during the visit of Fa- Hian. Describing Rajgir, Fa-Hian has mentioned “(Chap XXVIII) On leaving the town on the south side, at the distance of four “li” you come to a valley which leads to the “five hills:” these five hills form a girdle, like the walls of a town: this is the ancient town of the king “Ping-Cha” (the Old Rajagriha). From the east to the west is six “li”, and from the north to the south seven or eight; this is the place where “Che-li-foe” and “Mou lian” first met O pi (Aswajit). At the north east angle of the town the ancients erected a chapel in the garden, where An-pho-lo invited Foe and twelve hundred of his disciples to do them honor; this chapel still exists. The town is entirely deserted and uninhabited.” 

The ruins of Rajgir have been studied by British surveyors and archaeologists like Buchanan, Kittoe, Cunningham, Broadley, Beglar, Stein, Marshall and others. A regular and systematic survey of the ruins of Rajgir was made in 1905-06 by the Archaeological Survey of India, being supplemented later in 1913-14 by Jackson. In 1905-06 some excavations were undertaken by Daya Ram Sahni and Bloch. In 1950, A Ghosh did some trial digging, while in 1954 some excavations were carried out by D.R.Patil. 

To be continued.....