《淮南子·兵略训》
观察选择地形，安排宿营地址，修筑军营围墙，审察查明路障，驻扎高坡山地，营地能进能退：这就是善于利用有利地形。
相地形，处次舍，治壁垒，审烟斥，居高陵，舍出处，此善为地形者也。
To observe and select the terrain, arrange the camp address, build the camp walls, check and determine the roadblocks, station on the steep slopes and mountains, the camp can advance and retreat.