Bihar Dhap is an archaeological site located in Shibganj Upazila of Bogra District. This structure, situated on the banks of Nagar river, is also popularly known as Totaram Pandit's step or Totaram Pandit's house to the locals. The vihara is believed to be a vestige of the second construction period, and the site collapsed between the eleventh and twelfth centuries. Chinese traveler Hiuen Tsang's account mentions high mound-shaped temple steps unearthed from underground.
250 meters in length and 220 meters in width, Bihar Step is situated at a height of about 2 meters from the ground. Excavations have revealed a vihara measuring 57 meters north-south and 61 meters east-west. The open courtyard consists of an open courtyard surrounded by 37 monks' rooms, an entrance arcade with two guard rooms outside on the west side, and an altar to the east.
Bihar phase was continuously excavated from 1979-1986. Initially, the infrastructure of two Buddhist monasteries and a temple was partially recovered. Later excavations in 2005 revealed the remains of another temple from the east and the remains of five constructional structures. After the first construction period temple was damaged, in the second construction period, a new temple was built on the western side connecting the old temple, and the second temple built in the second construction period was rebuilt with the ruins on the western side. More than 1000 different types of archaeological artefacts are found from Bihar Step. Among them are silver coins of Sultan Sikandar Shah, bronze meditating Buddha, glass beads, 60 terracotta plaques, burnt clay seals, censers, pyreches, earthenware and carved bricks.