The Undavalli Caves date back to the 7th century BC and are prime example of rock-cut architecture. The caves are about 8 kilometres from Vijayawada and offer a unique perspective into ancient religious practices. The caves are carved out of sandstone on the side of a hill. While there are many caves, the largest is the one that is most popular for its huge monolith of Lord Vishnu in the reclining posture. The main cave is a prime example of Gupta architecture style, which concentrated on primitive rock-cut monastery cells.