The caves consist of temples and sanctuaries hacked out of huge granite outcrops. Their interior surfaces are remarkably smooth, and some are thought to have served as retreats for Jain monks.
Drawing inspiration from ordinary huts, the Barabar Caves are designed to look as if they're made of wood. The facade of the Lomas Rishi cave, which is sculpted to resemble lattice screens, is the first available example of famous Buddhist Chaitya arch style in India.
On the southern face of Barabar hill lies the earliest cave shrine known as the Sudama cave, anciently known as Nigoha-kubha or Banyan tree cave. This cave, excavated in the 12th regal year of Ashok (2 B.C) is a two- chamber structure and the interior surface of the cave is polished to a high degree and gives an impression of a layer of glass laid on stone.
Karan Chopar, a single-chamber-structure with a vaulted roof and simple opening in the rock face lies to the north of this cave. This cave was chiseled in the 19th regal year of Ashoka. Early inscription refer it as Supriya cave while later inscriptions call it with various names like Bodhimula (The root of intelligence), Daridra Kandara (the cave of the poor) etc. About 1000 yards east of this cave lies the fourth two-chamber cave -- Vishva Zopari excavated in the 12th regal year of Ashoka.