The mound of Bihar is only a kilometer south of Bhasu vihar and encircled y the Nagar river .It was excavated in 1979-83.The major discovery has been that of a monastery, the plan of which has been full obtained .It measures 57 m by 61 m and contains 37 monastic cells in all around the open courtyard: 10 each in the northern and southern wings 8 in the eastern wing and 9 in the western wing . The gateway projects outward from the center of the eastern wings. It was flanked on the outside probably by two guardrooms which survive in the form of two structures, each measuring 6.33 m by 5.9 m. A staircase led to the outer hall which also contained a brick platform with a semi circular structure at the base .The inner entrance hall is linked to the inner verandah from where a staircase with 3 steps goes down to the open courtyard .The monastic cells measure 3.3 m -4.5 m by 3.3 m. The partition walls are 1.5 m thick. The outer wall of the monastery which also the back wall of the monastic cells is 2.6 m thick while the thickness of their front walls 2 m . The lone surviving example of a door is 1.4 m wide. In two cell s of the eastern wing pedestals for image shave been found .The verandah is uniformly 2.7 m wide , with the western part of the southern wing showing a brick platform . The thickness of the retaining wall of the verandah varies from 1.3 m in the eastern and western wings to 1 m in the northern and southern wings . Deep digging revealed to conductional phases of the monastery, one built on the top of another without any alteration in the layout .The ruins of possibly another monastery were exposed to the south of this monastery the outline of which could not be fully obtained. Five monastic cells were excavated. One of them was found to possess a 2.2 m square platform . The back wall of these cells id 2.5 m thick and the thickness of the front wall is 1.8 m. The partition wall is 1.2 m thick. The southeastern portion of the mound showed the ruins of a temple with a high superstructure based on an irregular series of blind cells. It appears that the sanctum of the superstructure was built over the massive squares central cell of the cellular structure. This central cell internally measures 4.6 m N-S by 4 m E-W and externally 9.6 m N-S 9 m E-W. The massive eastern and western walls of the cell are 2.7 m wide and northern and southern walls are 2.5 m wide. Other subsidiary cells encircle this central cell in several rows on its four sides .The major antiquities discovered at the site are one silver coin of Sultan Sikandar shah , thirteen terracotta plaques , two terracotta seals, a few decorated bricks , miniature earthen pots , oil lamps , lids , glass bead ,terracotta beads balls toys,, net sinkers, bronze pieces , red , ochre’s , and iron nails.