Qin ling
Stretch across China Eastern qinling, white stone mountain west near tam county, gansu province, east longitude tianshui maijishan, through shaanxi, henan, about 1600 km, the north and the south tens of kilometers to a wupan km wide, majestic.
the towering qinling has created the guanzhong males. "Four solid plug thought" the guanzhong basin (shi-ji Liu Jingshu Sun Tong upright). The guanzhong "four," the east, south, west three plug into by the qinling mountains, the east huashan, Wang Shunshan, mount li, east real food, mountains, stand in the Yellow River and waterinfo between; The south taibai mountain, mount zhongnan, etc，cut off in western guanzhong. Another plus YaoShan, Huang Longshan vistas of mountains in the north and together make up the guanzhong and surrounded the terrain. Around mountains between rolling, mountainous, with many in north-west narrow.
For its all around has: east to tongguan or letter of valley, south is close, west to scatter, north to Xiao Guan. Tongguan is east into the guanzhong's natural defenses, the south qinling, have nutrient-laden los of the Yellow River and to the north, built in the south qinling shuhe ShangShan GuJian, deep cliff, so-called "fortress integrating ecology"; Scatter off the west the conjugate traffic arteries in guanzhong plain, south in accordance with the qinling mountains, is the throat of shu qin exchanges and the mohican. The other northern Xiao Guan r LiuPanShan foothill, KongE camels the arteries to the guanzhong. Because of qinling, the guanzhong into can attack and retreat and defend, formed "within the system of imperial" good momentum. Occupy the guanzhong, means that the mastery of the world "essentials", throttled kyushu "throat".