万里长城是我国古代的一项极为重要的军事工程,它东起河北的山海关,横跨山西、内蒙、陕西、宁夏、西迄甘肃嘉峪关,全长一万二千多华里。远在战国时代(公元前475—221年)万里长城就开始修建。当时主要是为了防御北方诸侯国和游牧民的滋扰而建的防卫性城墙。秦(公元前221—207年)续建,形成了西起临洮,东至辽东的万里长城,现存长城是秦汉之后,经北魏、北围、北齐的隋、宋、元各
The history is the aged with best memory. The 50-year-long China Railway Shisiju Group Corporation No. 2 Company with glorious histories has built Beijing-Jiulong Railway, Qinghai-Tibet Railway, Beijing-Shanghai Expressway and other key projects in the vast land of China. The Company has obtained one and another award of national and provincial excellent projects, created one and another perfect records and staged one and another splendid stories. Si Ma Tai Tunnel, the “No. 1 Tunnel of the Great Wall”, witnesses the excellent performance of this “Railway Army” once again.