text: In early medieval era, Viharas became important institutions and a part of Buddhist Universities with thousands of students, such as Nalanda.  Life in "Viharas" was codified early on. It is the object of a part of the Pali canon, the Vinaya Pitaka or "basket of monastic discipline".  Shalban Vihara in Bangladesh is an example of a structural monastery with 115 cells, where the lower parts of the brick-built structure have been excavated. Somapura Mahavihara, also in Bangladesh, was a larger vihara, mostly 8th-century, with 177 cells around a huge central temple.
  Variants in rock-cut viharas
  Usually the standard form as described above is followed, but there are some variants. Two vihara halls, Cave 5 at Ellora and Cave 11 at Kanheri, have very low platforms running most of the length of the main hall. These were probably used as some combination of benches or tables for dining, desks for study, and possibly beds.  They are often termed "dining-hall" or the "Durbar Hall" at Kanheri, on no good evidence.
  Cave 11 at the Bedse Caves is a fairly small 1st-century vihara, with nine cells in the interior and originally four around the entrance, and no shrine room.  It is distinguished by elaborate gavaksha and railing relief carving around the cell-doors, but especially by having a rounded roof and apsidal far end, like a chaitya hall.
  History
  The earliest Buddhist rock-cut cave abodes and sacred places are found in the western Deccan dating back to the 3rd century BCE. These earliest rock-cut caves include the Bhaja Caves, the Karla Caves, and some of the Ajanta Caves.