About 5 kilometers west-north-west of Old Town Bhubaneswar (as the crow flies) lie the adjacent hills of Udayagiri and Khandagiri. On them are carved multiple rock-cut caves that constitute a Jain monastery, dating back to the 1st c BC.
The bigger and more impressive caves are on Udayagiri, with the biggest being Cave 1, known as Rani Gumpha (queen’s cave). While the caves were originally carved in the 1st c BC, changes were made to some in later centuries. On the top of Udayagiri is the base of an apsidal structure which was a structural Jain temple (possibly wooden) from the 1st c BC. Here are photos from the monuments:
View of Udayagiri Hill from Khandagiri
The base of an apsidal structure at the top of Udayagiri. Khandagiri hill can be seen in the background of the first photo, with a 19th c Jain temple on top.
View of Bhubaneswar from Udayagiri
Cave 1, Rani Gupmha
Monastery cells on the lower level
Inside a cell
Looking along the verandah of the upper level
Reconstructed floor inside one of the cells