Agam Kuan is known to be the oldest and the most important archaeological sites in Patna. Agam Kuan, which means "unfathomable well", is said to date back to the period of Maurya emperor, Ashoka (r. 268–232 BCE). The well is located east of Patna, Bihar state, India, south-west of Gulzarbagh Station.
During the 1890s, the British explorer, Laurence Waddell, while exploring the ruins of Patliputra, identified Agam Kuan as the legendary well built by Ashoka for torturing people, a practice reported by Chinese travellers (most probably Fa Hien) of the 5th and 7th centuries A.D.
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