Xijiyu is 4.5 kilometers west of Dongjiyu. Like Dongjiyu, it’s one of four islands included in the South Penghu Marine National Park. Basalt sea cliffs for distinct columnar joints line the west and north sides of the island, stretching for hundreds of meters, a magnificent sight. Xijiyu was also part of the Penghu South Sea Basalt Nature Reserve. Everyone in Xijiyu moved away in 1978; the island is now uninhabited. To land on the island, you must first apply for a permit.

Although most of the houses are dilapidated, the outlines of the settlement are evident. The ruins of Xiji Temple, the island’s religious center, and four stone towers erected to ward off evil spirits are still here . On the northwest side, “vegetable houses”––low, basalt enclosures built to protect crops from the northeast monsoon winds––are intact, even though the village has long been abandoned. Former Xiji residents return for a few days each year to celebrate major holidays, such as Dragon Boat Festival and the Mid-Autumn Festival, taking the younger generation on a journey to find their roots.

The sea cave on the island's northwest side is the island’s best-known scenic spot. Locals called it the “stove” because it’s shaped like the mouth of an old-fashioned stove. Refracted sunlight turns the seawater around the cave sapphire blue, so it’s also known as the “blue cave.”

The island’s east and south sides are rocky shoreline. In the intertidal zone in the northeast, seawater eroded concavities in the rock either formed basalt potholes or expanded into "tide pools.” Like the “blue cave,” this geological wonder is well worth a visit.