Ice cave in the Skaftafell National Park in Iceland. Ice caves collapse and new ones form as each glacier grinds slowly towards the sea. Local guides can help you (without dying) find one. (Visit Skaftafell National Park in Iceland.
The cruise tour to the caves starts from Albufeira Marina in the city of Albufeira. During the cruise you will have the opportunity to discover fantastic caves such as Cathedral cave and other - Portugal (via Benagil Cave, Algarve, Portugal
Explore the ancient caves of Hang Son Doong, Vietnam. Hang Son Doong is one of the largest caves in the world and features a fast-flowing underground river. For spelunkers, exploring Hang Son Doong is the equivalent of scaling Mount Everest.