On the wild land near the northwest outskirts of Yinchuan lie two ancient castle relics, forming the famous Zhenbeibao ancient town. This two castles serving as fortresses, were built in the period of Qing Dynasty and Ming Dynasty to defend invisions by tribes on the north side of Helan Mountain, that’s why Zhenbeibao got its name. Local people call the two castles as "New Castle" and "Old Castle". According to local records, the Old Castle was built in the 13th year under the reign of Emperor Hongzhi (1500AD) in Ming Dynasty, while the new one was built in the 5th year under the reign of Emperor Qianlong(1740) of Qing Dynasty.
All standing west and facing east, the two castles respectively locate in the north part and the south part. The Old Castle, on the east side of the road at the foot of Helan Moutain, has been decayed to ruins, only the figure of which remains. The Old Castle stretches 175meters long from east to west, 160meters wide from south to north. The bulwark relics of the Old Castle are at the north end of the city path. To the north of the Old Castle, the New Castle lies 200meters away. The new castle has complete structure, 170m long from east to west, 150m wide from south to north and about 10m high. To the north stands a semi-circle bulwark, from south gate of which a slope can send you to the city wall. Five meters high, the wall has crenels of 1.8m high. At the four corners of city wall once was built four watchtowers, whose bases are also faintly visible.