The once-abandoned village is now a popular tourist attraction.(Photo:China Daily/Sun Ruisheng)
Diantou resembles a beehive from outside. Inside, it's an ant farm.
A web of tunnels that stretches hundreds of kilometers connects the caves.
The altitude and gradient would make it difficult for attackers to enter the caverns. But once inside, getting from chamber to chamber is no easy task. The passageways are punctuated with shelters, peepholes and one-way doors-not to mention secret chambers with air vents used to store grain.
One passageway bores deep into a nearby mountain cave that spurts water.
While the village is pocked with wells, the mountain spring is believed to have become the primary water source when Diantou was besieged.
Villagers also used the tunnels to hide from bandits and Japanese invaders during the War of Resistance Against Japanese Aggression (1937-45).
But many became clogged during the peaceful period starting from the 1950s.
Li has cleared hundreds of meters of tunnels that connect several main cavities and installed sound-activated lights. Excavations are ongoing.
Yet while Diantou existed primarily as a military outpost, it also hosted entertainment and religious facilities.
A tumbledown theater stage faces collapsed bleachers in the shadow of two ancient locust trees in the west of the village.
A "light wall" nearby is bedecked with a candelabrum. Farmers still ignite 365 oil lanterns on the first day of the Lunar New Year and keep them burning until Feb 2 on the traditional Chinese calendar. The ritual seeks blessings for the coming year.