Gubeikou Great Wall is on the north of Tiger Mountain, which has in it an indentation one meter in diameter and 20 cm deep called the Spring of Heaven. The water from this spring flows continuously in both the rainy and fry seasons. Near the spring is a defense tower called the Five Eyes Tower. Unique in design, the body of the tower is made of rectangular stone blocks and the roof of polished bricks. Inside there are two large barrel-vaulted ceilings, three corridors, 10 arched openings and a central octagonal dome supported by four brick columns arranged in a square. The stone columns are decorated with relief carvings of flowers, which add a touch of elegance to this otherwise austere building. Standing atop this tower, one can see the Great Wall winding its way along the contours of the mountains. From this vantage point, the wall appears like a ribbon of jade linking the Wuling Mountain (the highest peak of the Yanshan Range) with the Sleeping Tiger Range near Gubeikou.
Gubeikou is 125 kilometers away from Beijing . It has long been a town of military significance and an important passage to the capital city. The Yanshan Range winds from east to west and is cut off at Gubeikou, forming a natural narrow pass here.