The Yongdingmen Gate is also known as Zhengyang Outer Gate, which means "eternal stability". Yongdingmen Gate Tower was initially built in the 32nd year of the Jiajing Period in the Ming Dynasty, which was the former front gate of the outer city of Beijing's old city wall in the Ming Dynasty, with magnificent architectural scale. The current Yongdingmen Gate Tower was rebuilt by Beijing Municipality in 2004 following the style of the Qianlong period. The main buildings include the gate platform, the archery tower and the enceinte, forming a complete city defense architectural system. Today, Yongdingmen Gate Tower is the southernmost landmark building on Beijing's Central Axis.