The cave has long been poetically associated with human history. Until the post-Stone Age, caves were also crowded with inhabited people.
But later on, people no longer use caves as shelter. The ancients have woven many strange mysteries related to caves. The ancient Greeks believed that the cave was a temple, home to gods such as Jupiter, pan, Dionysos, and pluto … the ancient Romans believed that the cave was home to the “nymphs” ( fairies) and sibyl. The ancient Persians linked the cave with Mithra’s worship, the lord of ghosts on the ground. Today, giant and beautiful caves around the world are attractive tourist sites.
A cave is a place deep in a mountain, hill, or cliff. Large caves are called caves. The cave is structured in many ways. There is a cave created by the continuous waves of the sea. There is a cave deep in the ground. these caves are created by groundwater currents that erode layers of soft rock – such as limestone -. There is a cave created by a volcano.
The most common caves in the United States are caves due to groundwater erosion. Carbon dioxide is contained in this groundwater. In Indiana, Kentucky, ten Tennessee, there are very large limestone beds with an average thickness of 55 m. So there are many caves here. There is a cave with ventilation holes through the ceiling. At first, this hole was just a small hole, even just a crack. The water above seeps down the fold and spreads wide. There is a cave with corridors, with two or three floors overlapping. Eroded groundwater currents form a deep cave, then, at a different part, encounter an obstacle, the water current creates a different or lower passage. So it flows in a different direction, creating a new cave and leaving the old cave. This cave becomes dry.
In many cases, water droplets from above the ceiling soak through the limestone. These water droplets contain calcium and many other metals. The bottom opposite to the drop formed a stalactite; for a long time, these two stalactites were connected, called stalagmites.