Built during the Maurya Empire (322-185 BC), the Barabar caves are the oldest rock-cut caves in India. These man-made caves are located in the twin hills of Barabar and Nagarjuna. The Barabar group bears dedicatory inscriptions in the name of “King Piyadasi,” and the Nagarjuna group in the name of “Devanampiya Dasaratha,” probably dating back to the 3rd century BC. The caves were used by ascetics from the Ajivika sect, which developed during the same period as Buddhism and Jainism.
Dating from the 3rd century BC, the Barabar Caves are the earliest example of rock-cut architecture in India.
The Barabar Hills contain four rock-cut caves, namely Karan Chaupar, Lomas Rishi, Sudama, and Visvakarma. Sudama and Lomas Rishi caves are the earliest examples of rock-cut architecture in India. Most of these caves consist of two chambers carved out of granite with polished internal surfaces. According to the inscriptions inside the caves, these four caves date from the period of Emperor Ashoka (reigned 273-232 BC). Later, Dasaratha Maurya, the grandson of Ashoka, dedicated three rock-cut caves on the Nagarjuna Hill to the Ajikiva sect. These are the Gopika, Vadithi-ka-Kubha, and Vapiya-ka-Kubha caves.
Lomas Rishi cave is probably the most famous of the caves due to its elaborately carved arch-like façade. On its doorway, a line of elephants proceed towards stupa emblems which is the characteristic form of the “Chaitya arch.” With these features, the façade of the cave is clearly a stone imitation of contemporary wooden architecture. The construction of this cave began around 260 BC; however, it was left unfinished due to structural problems.
On the left side of the Lomas Rishi cave is the Sodama cave, consisting of two chambers. The rectangular one measures around 10×6 meters and the semi-hemispherical chamber is 6 meters in diameter. According to the inscription at the entrance of the cave, Emperor Ashoka consecrated the cave in 257 BC. The perfectly polished internal surface of the cave creates a mirror effect and also reverberates the sound. It was a common feature for all the caves in both hills.