Any great wall needs at least one great pass, and, by Chinese estimation (they ought to know), Juyongguan is one of three great passes punctuating the ancient defensive line as it wends its way across northern China. The other two mark either end of the Great Wall, with Shanhaiguan to the east overlooking the Yellow sea and Jianyuguan far to the west, marking the western extremity of China's most famous—and the world's largest—landmark.

The pass, a convenient 50 kilometers north of Beijing, is actually the 18 kilometer-long Guangou Valley in which numerous battles have been fought and where Chinese dynastic leaders, starting with the first Qin emperor in the third century BC, have ordered massive defensive works built to protect against frequent forays by aggressive Mongol and Manchu tribesmen.

At the northern reach of the pass is the site of Badaling, the most-visited point on the Great Wall, where it runs along rugged ridges and steep slopes. The southern end is known as Nan Pass, and in between the two you'll find the Cloud Platform, a monumental watchtower made of white marble erected during the Yuan Dynasty by the Mongol conquerors whose ancestors had been held at bay for so long on the other side of the Great Wall.

At the tower's base, a broad carved archway once let soldiers and warhorses pass through; today, it hosts visitors who come to see the carvings of animals, gods and characters.

The area has changed much over the years, experiencing periods of hubristic monument and fortification building alternating with times of destruction, as one dynasty gave way to another. The present pass is much as the Ming left it, though it has, of course, experienced intensive renovation. The valley and its landmarks make for a lovely spring or fall outing, when the grasses, flowers, trees and weather are all likely to be at their best.