The Barabar Caves are the oldest rock-cut caves in India, dating from the Mauryan period (322–185 BCE), and some with Asokan inscriptions. They are located in the Jehanabad District of Bihar, around 24 km north of Gaya. They were built for the Ajivika sect, which had been founded by Makkhali Gosala, one of the six famous teachers during Lord Buddha's time.

Four of the caves are situated in the twin hills of Barabar and three on the nearby Nagarjuni Hill. Some of these rock-cut chambers date back to the 3rd century BC and were prepared under the command of Emperor Asoka (r. 273 BC to 232 BC). Later his grandson, Dasaratha had the caves at Nagarjuni excavated. These caves then formed the precedent for other cave complexes like Ājānta and Ellora.

The caves at Barabar are carved entirely out of granite, with a highly polished internal surface and deep echo effect, and some of them consist of two chambers. The first chamber was possibly meant for worshippers to congregate in a large rectangular hall, and the second, a small, circular, domed chamber was for meditation, this inner chamber possibly had a small stupa like structure at some point, though they are now empty.

Though the Emperors were Buddhists themselves, they allowed various ascetic sects to flourish under a policy of religious tolerance. Although the caves were originally excavated for the Ajivikas, Buddhists, and perhaps other sects, later inhabited them. The Nagarjuni caves are so-called because legend states that the great master Nagarjuna once resided in these caves.

It is perhaps worth noting that the central incident in E. M. Forster's novel A Passage to India takes place in a fictionalised version of these hills, there called Marabar. In the novel there are various discrepancies from the real caves, but the darkness of the caves and the echo are real enough.

On top of the Barabar Hill is the Hindu Siddheshvarnath shrine, which commands a fine view out over the rugged coutryside. On the way up to the shrine from the Nagarjuni side there are many reliefs carved into the rock face, and free-standing statues are found scattered about.

Kawa Dol is situated around 3km from the Barabar range, and has some excellent reliefs carved into the rock walls near the village. There is also a very fine Buddha statue in a small shrine near the village, measuring around 8ft tall, and probably dating from the 8th-9th centuries. It stands in the midst of a collapsed temple, only the columns of which survive.