The super guide of Simatai

Security guard who knows the Great Wall like the back of his hand is always ready to field questions from curious visitors, Yang Feiyue reports.

Hikers at the Great Wall who have come across Zhou Wenjun consider themselves lucky. The 44-year-old is more than a security guard; he is a walking encyclopedia on the man-made fortifications that made it to the UNESCO World Heritage List in 1987.

Zhou knows the subtle differences that set each of the 35 beacon towers apart, and he can fill you in on the salient features of ancient stones and bricks that make up the Simatai section of the Great Wall in Miyun district, northeastern Beijing. A voracious reader, he replenishes his knowledge of history every day, so that he can field questions from curious visitors. He often seeks expert advice to be on the top of his game.

"The Great Wall is an intriguing study. The ramparts and fortifications are well conceived and yet peculiarly designed to suit various sections of the mountains. Horse paths stretch from the gentle slopes and there are high stairs on the steep slopes," he says.