Situated on the coast of Tianfu Village, Black Devil Cave has a historical legend. During the Ming Dynasty, Zheng Cheng-gong drove the Dutch away and restored Taiwan, Penhu and Liuqiu. Some black slaves abandoned by the Dutch were found living secretly in the cave. In addition, during the Ching Dynasty, there were stone tables, stone chairs, stone beds, stone bowls, silverware, jewelry, etc. discovered in the cave.

Due to collapse, the entrance of the cave is still blocked.
According to an old legend, there was a tragedy that happened to the black slaves in the cave. As Liuqiu and Philippines stood far apart facing each other, the boats traveling between them often anchored off Gaben located north of Black Devil Cave in case of strong winds and waves. At night the cave-dwelling black slaves went into the sea and made a hole on the bottom of the parked boat. After the boat sank to the sea, they stole foods and all the property on it.

The situation happening over and over again drew the crews’ attention. After investigation they realized that the black slaves committed the crime. Then the crews found the cave and set fire to kill the black slaves. No black slave survived the fire and then no parked boat sank to the sea. On a slope near Black Devil Cave there are two big clam fossils embedded in the rocky wall. The two fossils are about one meter in diameter and hundreds of thousands years old and worth academic research. Black Devil Cave is the most famous tourist spot on the island.