Family preserves a piece of the Great Wall

Strange as it sounds, Yang Guoxing, a farmer in Northwest China, has lived inside the Great Wall all his life.

Yang's father grew up in a tiny village in Tongxin county in the Ningxia Hui autonomous region. When he married in 1950, he carried his new wife over the threshold of a cave house - dug through a section of the Great Wall. Such houses can be found across hillsides in northwestern China.

Unexpectedly, the presence of the cave houses has meant better preservation of parts of the ancient wall, because sections of it are enclosed and protected by a family's courtyard and kept intact. Old bricks from the wall sections outside the courtyards were often taken to sell or to use as building material.