Cheung Po Tsai Cave, Pirate cave in Cheung Chau Island, Hong Kong.

Cheung Po Tsai Cave is a natural cave on the southwestern shore of Cheung Chau Island in Hong Kong, at the edge of Sai Wan Cliff. Its entrance is a narrow gap between two rough stone faces, one marked with a painted white arrow and the character 洞. Inside, the passage runs about 88 metres from entrance to exit, is dark, slippery and uneven, and steel ladders have been added for access.

In the early 1800s a naval officer turned pirate used this cave as a hideout for plunder from raids. The site later became a focal point for legends and searches for lost treasure.

The site takes its name from a notorious sea captain whose stories islanders still retell today. Locals and visitors walk through the chambers imagining how pirates once stored loot and organized their ships.

Visitors need flashlights to see inside the dim passages and should wear sturdy shoes. The trail from the ferry pier is steep and takes roughly half an hour on foot.

The cave is a natural formation, not a carved tunnel, and no treasure has ever been found inside it. In April 2012 a large number of stones fell and narrowed the entrance. The Amazing Race 17 filmed a segment here during its tenth episode.