The name Bhasu Vihar was first used by cunningham and since then it has been current in the archaeological literature ,The mortee common name is ‘Vasu Vihar’.The site of the complex is about 3-4 miles to the northwest of mahasthangarh , There are two villages Bihar and Bhasu Vihar- both across the Nagar river which is a branch of the karaoya which has formed a loop along the whole of the eastern and southern boundaries of these villages .Bhasu Vihar lies in the north while Bihar lies toi its south.Three mound s and a large number of tanks in these two villages . The mound in Bihar is listed as 300' by 200' by 6' . The two mounds in Bhasu Vihar are reported to have measure 60′ by 60′ by 7′ and 800′ by 750′ by 40. The smaller mound lies to the west of the Bhasu Vihar mound. About he place and the mound. The Nagar was once a much larger river with a river port alled Bihar Bangar nearby . The undated but presumably pala period earthwork which begins in the Pabna area and can be traed intermittently up to the Rangput district also passes through this region. This earthwork is known Bhimwe Jangal, The larger of the two Bhasi Vihar mound is locally known as Narapatir Dhap. It is a complex of five mounds , three large and two small. The ancient occupational remains are said to have extended considerably beyond the limit of the mound proper . The site site is surrounded by a moat-like depression on all sides except for a part of the west but one cannot be sure of the issue. The one reported by cunningham has now been filled up but the tank to the south of the site still exists and is known as Khingrailer Dighi. On the basis of his wide experience of Buddhist sites in Bangladesh, There have a large water tanks are invariably found associated with ancient ruins in Bengal . specially of the Budhist culture , In fact, a large Budhist establishment without a tank of comparable size is almost unheard of in bangladesh .The second mound which lies less than half a male to the west northwest of Bhasu Vihar is known as sannyasir Dhap There is tank known as sasanker Dighi to the south of the mound. This possibly contains the ruins of a small temple.a monastery named po-shi-po was situated 4 miles to the west of Mahasthangarh and this tallied with the position of Bihar in relation to Mahasthangarh .This brought that it was this name which was related to the chinese pilgrin’s po-shi-po :here the pilgrim found a grand monastery ,remarkable for the size and height of its towers.It was occupied by no less than seven hundred monks,who studied the Mahayana and men famous for their learning flocked here from the eastern districts,At a short distance from the monastery there was a stupa built by asoka , on the site where Buddha had explained his law to the Devas.Near this was a spot where the last four Buddhist had taken exercise and rested.