Nhi Thanh Cave is a natural limestone cave located in Lang Son Province, Vietnam. It is known for its stunning stalactites and stalagmites, which have formed over thousands of years. The cave is a popular tourist destination, attracting visitors who come to explore its unique geological features and enjoy the cool, refreshing atmosphere inside. The cave also holds historical significance, as it was used as a shelter during various conflicts in Vietnamese history. Today, Nhi Thanh Cave is part of a larger tourist complex that includes beautiful landscapes and cultural sites, making it a key attraction in the region.