An underground battleground

Diantou's caves were carved to enable imperial soldiers to vanquish invaders without leaving their subterranean fortifications. Li Yang and Sun Ruisheng explore these little-known grottos and tunnels in Taiyuan.

Diantou village's honeycomb of ancient cave dwellings conjures an allure that today draws a diverse cast of characters - adventurers, painters, photographers, architects, military-history fans, archaeologists, filmmakers, historians, monks, Taoists, anthropologists and shepherds.

The complex of caverns is whittled into the mountainsides over a 1-kilometer stretch overlooking a river that runs parallel to the main road connecting Taiyuan, which today is Shanxi's provincial capital, to the outside world.