The Drum Tower, which is an important part of Drum Tower Park, lies on the Purple Mountain. It is 44 meters long, 22 meters wide and 30 meters high. Its shape is like a Chinese traditional city gate, with a square foundation pedestal made of stone. In the pedestal, there are three arch gateways, one larger in the middle and two smaller on the side. In the side gateways, there are four side-rooms, which were guarded by the imperial drumming officers with hundreds of soldiers during the ancient dynasty. On the pedestal is a red two-story watch tower, made of wood and bricks, which was a sacred place to hold some important ceremonies, such as giving a correct time, welcoming honorable guests, offering sacrifices to the god, and others.