You'll have to rely heavily on your imagination to envisage what was once one of the greatest cities in the ancient world, ruled by kings Ajatasatru (491–459 BC), Chandragupta (321–297 BC) and Ashoka (274–237 BC). There's barely anything to actually see, except the sandstone remains of a pillar. Nothing remains of Ashoka's 80-pillared hall, thought to be the location of the third Buddhist Council. There's a small museum.
Shared autorickshaws (₹10) run to the site from just outside Patna train station.