12. Caves

Caves come in all different shapes and sizes depending on how they were formed. Spelunkers (people who explore caves) have plenty of descriptive names for caves and the natural rocky features that form within them – soda straws, fried eggs, popcorn and draperies are just a few. Caves can be as simple as one straight passage with a few stalactites overhead, or as complex as a labyrinth, with many stalagmite-carpeted rooms.