相信很多人都知道,老北京城是以正阳门、天安门、午门、地安门等为中轴线对称分布的格局,但是,很少有人知道,这条中轴线的南端是永定门。永定门是老北京外城上的正门,虽没有正阳门、天安门般地位尊贵,为人们所熟知,但它却是外城城门之中唯一一座拆而复建的城门。 I believe many people are aware that the old Beijing city is a pattern of axisymmetric distribution centered on Zhengyangmen, Tiananmen, Meridian and Diane. However, few people know that the southern end of the central axis is Yongdingmen. Yongding Gate is the main gate of the old Beijing outer city. Although it has no Zhengyangmen Gate and Tiananmen Square status is distinguished, it is well known to all but it is the only demolished and reconstructed gate in the outer city gate.