1. Stalactites and Stalagmites: These formations are found in caves and are created by the slow deposition of calcium carbonate from dripping water. Stalactites hang down from the ceiling, while stalagmites rise up from the floor.

2. Karst Topography: This is a type of landscape characterized by sinkholes, caves, and underground drainage. It forms when soluble rocks, like limestone, are dissolved by acidic groundwater. This dissolution creates underground cavities and channels, and the material that is dissolved can be re-deposited elsewhere, forming features like stalactites and stalagmites.