Shalban Vihara, originally the Bhavadeva Mahavihara, was built by Bhavadeva, the fourth king of the early Deva dynasty, in the late 7th or early 8th century. It is one of more than fifty Buddhist sites along the Lalmai–Mainamati ridge.
The monastery is a square about 168 m a side, with 115 monks' cells ranged round a courtyard and a cruciform shrine at the centre. Excavation since 1955 has turned up copperplate inscriptions, gold and silver coins, terracotta plaques, seals and bronze sculpture — many now in the Mainamati Museum next door.
It is at Kotbari, about 10 km west of Cumilla city. Wear a hat; there is little shade on the brick walls.