Shanhaiguan (Shanhai Pass) became known as the "First Pass under Heaven" since ancient times. It is a major pass of the Great Wall, with strategic importance at its eastern beginning
Shanhaiguan had other names in ancient time that share the same pronunciation of “Yuguan”. Today’s pass city was built under the direction of Xu Da in 1381. Since it is close to a mountain and the Bohai Sea, it was named Shanhaiguan (the pass of mountains and the sea). It was a most famous pass of the Ming Great Wall, lying 15km to the east of Qinhuangdao, Hebei Province. To the north there is the Yan Mountain, and to the south there is the Bohai Sea. Its unique seat between the mountain and the sea enabled it to be a majestic and strategic stronghold. In ancient time it was an economic and cultural channel of communications for people dwelling inside and outside in the peacetime; in the wartime, it would become a place of contention.
The perimeter of Shanhaiguan is 4km. Its moat is 16m wide and 8m deep. The rampart is 12m high. On each side of the city there is a city gate. The eastern city gate faces the direction outside the Great Wall; call Zhendongmen (the east-guard gate). The western gate faces the inner pass, called Ying’enmen (the kindness-receiving gate). The southern gate faces the sea, called Wangyangmen (the sea-facing gate). The northern gate faces the wandering Great Wall, called Weiyuanmen (the majestic Great Wall-facing gate). Zhendongmen is the best kept one, on its huge platform there was built a battlement, i.e., the famous city tower entitled “the First Pass in the world”.
The battlement is 13.7m high, 10.1m wide from east to west, 20m long from south to north. The lower floor is 5.7m high, and the wall is .3m thick. The upper floor is 8m high, and the wall is 0.9m thick. The total building area is 198 square meters. It has the double layered saddle roof, the two eaves on the top ridge are symmetrical, under which there is brick-timber construction. On the cornices at the four angles there were decorated various attractive ridge animals. The eave purlins and the central portion of the beams inside and outside the building were painted with colorful drawings in the Ming style, charming and magnificent.
Outside the eastern and western gates were net cities. Outside the southern and northern gates there were wing cities. Still in the periphery of Shanhaiguan there dotted with wei, sui castles, cities and beacon towers that made up the complete defense system of Shanhaiguan.