!Bhismaknagar Bhismaknagar is in Lower Dibang Valley district of Arunachal Pradesh in India. It is famous as a sacred heritage of the Idu Mishmis and Bhismaknagar Fort. It is located at about 30 km from Roing. The fort is tentatively dated to 8th century and is recorded as the oldest archaeological site in the region. The site was first explored by I. Block in 1848 and afterward it was excavated during 1965-70. The complex houses the ruins of brick-built structure of 1860.52 sq metres plinth area, having three halls, two extension rooms and six entrances in all. This place is important of its age old civilization that propered here and the surrounding areas. It has become a symbol of past glory and indicate the high standard of civilisation. Bhismaknagar must have been a strong hold of the Chutiyas (12th-16th centuries). However, the recent excavations has been throwing new light on its much earlier antiquities. Bhismaknagar stands for what is best in the tribal and Aryans way of life. It speaks for the Catholic spirit of the ancient Indians and the contribution made by the Idus to the synthetic fabric of Indian culture.