Remains of a castle called Qaleh Pesar indicated that it stood on the northeastern highlands of Shapur mountain range on the right side of Shapur River and Tang-e Chogan. The slope on its eastern part is very steep with several cliffs which make it difficult to climb. Also ascending the mountain from its western, southwestern and northern ridges is hard because of its relatively steep slopes. Qaleh Pesar has been built at a higher altitude compared with Qaleh Dokhtar. In addition, it is a bit larger in size and has a little wider distribution of walls. As for the appropriate location and strategic position of Qaleh Pesar, it enjoys a full view of the upper and lower Tang-e Chogan, nearby plains as well as Bishapur.Therefore, it can also be concluded that the fortress served as a watch tower controlling various spots overlooking the city for defensive purposes.