It is one of the four fortresses of the Baoan ancient fort complex and a national key cultural relic protection unit. It was built during the Reign of Emperor Kangxi of the Qing Dynasty, it is rectangular in shape, 310 meters long from north to south and 90 meters wide from east to west. The walls were built of rammed earth and 10 meters high. Nianduhu village is famous for Rebgong art, known as the "pile embroidery" village, the national intangible cultural heritage- Tiger Dance of Tu Nationality is preserved here.