Great Wall explorer records unmapped ruins

Enthusiast spends 200 days a year in the wild taking notes and photos

Gripping self-made hiking poles, Li Shixiang picks his way along the sheer cliffs of the Yellow River's Heishan Gorge in Zhongwei, Ningxia Hui autonomous region, under the blazing sun.

The 49-year-old amateur archaeologist is searching for the remains of the Great Wall, which was mainly built on mountain ridges across northern China using rammed earth, stones and bricks.

The UNESCO World Heritage Site was constructed over the course of 2,000 years. It worked as a fortification system to defend against nomadic invasions.