Sung Sot Cave

Sung Sot Cave, also called Surprise Cave, is the largest cave in Ha Long Bay on Bo Hon Island, Ha Long City, Quang Ninh Province, Vietnam. Part of the UNESCO World Heritage-listed Ha Long Bay, it contains two large chambers filled with stalactites and stalagmites enhanced by colored lighting. Discovered by the French in 1901, it is reached only by boat via Ha Long Bay cruises and is renowned for its scale and karst scenery.

Visitors arrive by sightseeing boat at Bo Hon Island pier and climb about 50 stone steps through forest to the cave entrance. Inside, two vast chambers connected by a narrow passage display stalactites, stalagmites and karst formations illuminated with colored lights, with paved walkways and railings. The second chamber is expansive with high ceilings and natural openings. The visit includes views of Ha Long Bay's limestone islands from the approach and exit path.

Discovered by the French in 1901 and named Grotte des Surprises (Surprise Cave). Developed for tourism after Ha Long Bay's recognition as a UNESCO World Heritage Site in 1994, it has become the most visited cave in the bay.

Part of Ha Long Bay UNESCO World Heritage Site, representing the region's karst landscape and natural heritage. The cave is a central feature of Ha Long Bay tourism and local interpretation of bay folklore and geology.