中国封建时代的城市中,常有里坊制度。里坊的四周有围墙,墙中央为坊门,这种坊门多数是由两边两根华表中间加横梁或板门组成,称为“乌头门”,以后也称为“棂星门”,在宋代十分流行。后来,将这种“乌头门”单独设置于街心、桥头、路口、墓前,便逐渐发展成了“牌坊”、“牌楼”,成为一种纪念性的建筑物。 后来的牌楼又是从牌坊演变而来。牌坊只用华表加横梁,而牌楼则是在横梁之上还修筑斗拱、屋檐、飞檐起脊,如同楼顶,各牌楼的楼顶数量也有不同,有的仅有一楼,多则三、五、七 In the feudal era of China, there are often Li Fang system. Lifang surrounded by walls, the center of the wall Square Square, the square most of the two sides of the table by the middle of two beams or plate door composition, called “Aconitum”, later also known as the “Star Gate” in the Song is very popular. Later, this kind of “Aconitimen” was set up alone in the streets, bridges, intersections and tomb before gradually evolving into a “archway” and a “archway” to become a memorial building. Later arches evolved from the arch again. The archway only uses Chinese tables and beams, while the archway is also built on the beams above the arch, eaves, cornices from the ridge, as the roof, the arches of the roof of the number is also different, and some only the first floor, as many as three, five, Seven