Badami’s caves overlook the 5th-century Agastyatirtha Tank and the waterside Bhutanatha temples . On the other side of the tank is an archaeological museum , which houses superb examples of local sculpture, including a remarkably explicit Lajja-Gauri image of a fertility cult that once flourished in the area. The stairway behind the museum climbs through a sandstone chasm and fortified gateways to reach the ruins of the North Fort .