Kyaukgu Umin or Rock Cave Tunnel - is to the East of Nyaung U. This early temple is built into the inside of a cliff, with a high archway forming the main entrance. Around the entrance are impressive friezes and decorated door jambs. Opposite, at the back of a large square hall, is a large statue of the Buddha seated on a lotus throne. There are also niches with stones reliefs and painted panels. A series of tunnels with meditation chambers have been excavated deep into the hillside.
The main temple dates from the 11th century but the terraces and small stupa are believed to have been built by King Narapatisithu. It is dark inside; visitors should bring a torch.