About 8 km southwest of Vijayawada on the south bank of the Krishna, the Undavalli Caves are a four-storey rock-cut monastic complex hewn from a sandstone hillside between the fourth and seventh centuries. The main attraction is a colossal reclining Vishnu carved from a single stone, occupying most of the second floor.
The upper storeys are simpler but worth the climb for the views over the Krishna and the surrounding fields. The site is best reached by autorickshaw from the city; allow an hour for the visit. It pairs well with the nearby Amaravati ruins as a half-day archaeological loop.