Undavalli Caves are an impressive 4th–5th century rock-cut cave complex carved out of solid sandstone hills along the Krishna River. The multi-storeyed caves showcase early Indian sculptural and architectural styles influenced by Buddhist, Jain, and Hindu traditions. The highlight is a massive monolithic reclining Vishnu idol on the second floor, attracting thousands of visitors each year. Surrounded by greenery and offering stunning viewpoints, Undavalli Caves are one of the most iconic heritage sites near Guntur and Vijayawada.