Explanation:

It is typical example of early cave architecture is the most datable cave of all, the so-called Lomas Rishi cave in the Barabar Hills of Bihar.
It was built during the Ashokan period of the Maurya Empire in the 3rd century BC, as part of the sacred architecture of the Ajivikas, an ancient religious and philosophical group of India that competed with Jainism and became extinct over time.
An inscription proves that this was excavated for the Ajivika sect in the time of Ashoka himself. The cave carved out of the living rock, measures 55'x22'x20'. The entrance is a representation in stone of a hut entrance, with the end of the roof constructed of bent timber supported by cross beams, the ends of which are shown protruding
The Barabar Hill Caves are the oldest surviving rock-cut caves in India, mostly dating from the Maurya Empire (322–185 BCE), some with Ashokan inscriptions
These caves are situated in the twin hills of Barabar (four caves) and Nagarjuni (three caves)
hese rock-cut chambers date back to the 3rd century BCE, Maurya period, of Ashoka (reigned 273–232 BCE) and his grandson, Dasharatha Maurya

The sculptured surround to the entrance to the Lomas Rishi Cave is the earliest survival of the ogee shaped "chaitra arch" or chandrashala that was to be an important feature of Indian rock-cut architecture and sculptural decoration for centuries. The form was clearly a reproduction in stone of buildings in wood and other plant materials.

The caves were used by ascetics from the Ajivika sect, founded by Makkhali Gosala, a contemporary of Gautama Buddha, the founder of Buddhism, and of Mahavira,