Speleology is the scientific study of caves and other karst features, as well as their composition, structure, physical properties, history, ecology, and the processes by which they form and change ov
Grotte des Faux-Monnayeurs, Mouthiers-Haute-Pierre (France)
Beam of sun inside the cavity of Rocca ill'Abissu, Fondachelli Fantina, Sicily
Pirunkirkko (literally "devil's church") of Paistjärvi, a peak cave in Heinola, Päijät-Häme, Finland
Cave labeled with the six most common types of speleothems: flowstone, columns, drapery, stalagmites, stalactites and straws
Caves and caverns are natural voids under the surface of the Earth and have also been observed in other rocky worlds. Caves often form by the weathering of rock and can extend deep underground. Exogen
Speleology
…Speleology (from Ancient Greek σπήλαιον (spḗlaion) 'cave' and -λογία (-logía) 'study of') is the scientific study of caves and other karst features, as well as their composition, structure, physical properties, history, ecology, and the processes by which they form…
Lechuguilla Cave, New Mexico, United States
Speleothems in Hall of the Mountain King of Ogof Craig a Ffynnon, a solutional cave in South Wales.
Exploring a lava tube in Hawaii.
Painted Cave, a large sea cave, Santa Cruz Island, California