Bell Tower and Drum Tower were originally used as musical instruments in China. Afterward, however, they were used for telling time. As early as in the Han Dynasty (206 BC-220), there was a morning bell and a dusk drum. Telling the time by them played an important role in helping people live and work regularly when there was no other means to keep track of the time. As a result, they became public architectures, and were widely constructed in almost every city throughout the country since the Han Dynasty. In the history of their construction, they are the largest and highest. Their layout is unique, in that they were placed fore-and-aft, not as the traditional sense of standing right-and-left horizontally.
Xi’an Bell Tower marks the geographical center of this ancient capital. The tower was built in 1384 by Emperor Zhu Yuanzhang as a way to dominate the surrounding countryside and provide early warning of attack by rival rulers. From the Bell Tower extend East, South, West and North Streets, connecting the Tower to the East, South, West and North Gates of the City Wall of the Ming Dynasty. The wooden tower, which is the largest and best-preserved of its kind in China, is 36 meters (118 feet) high. It stands on a brick base 35.5 meters (116.4 feet) long and 8.6 meters (28.2 feet) high on each side. During the Ming Dynasty, Xian was an important military town in Northwest China, a fact that is reflected in the size and historic significance.
The Drum Tower is located northwest of the Bell Tower of Xian. The Drum Tower and the Bell Tower are called the 'sister buildings' or 'morning bell and dark drum'. In ancient China, especially from the Yuan Dynasty (1271-1368), the drums were used to signal the running of time and on occasion were used as an alarm in emergency situations. The Drum Tower is a two-storied post and panel structure, 34 meters (about 112 feet) high, 52.6 meters (about 172 feet) long from east to west, and as 38 meters (about 124 feet) wide from north to south. The architecture style of the Drum Tower is a combination of the styles of the Tang Dynasty (618-907) and the Qing Dynasty.