draghål

A draghål, meaning "draft hole" in Swedish, is a geological feature consisting of a vertical shaft or tunnel that connects the surface of a cave or underground system to a lower level. These formations are typically created by the erosion of soluble rock, such as limestone, by flowing water. Over geological time, water seeps through cracks and fissures, gradually widening them into shafts. The process can also be influenced by tectonic activity that creates fractures.

Draghål can vary significantly in size, from narrow chimneys only a few feet across to massive, cathedral-like shafts hundreds of feet deep. They are often characterized by their smooth, water-worn walls and can contain stalactites and stalagmites if the conditions are right for mineral deposition. These features are important for cave ecosystems, facilitating the movement of water, air, and organisms between different levels of the underground environment. Explorers often encounter draghål when navigating complex cave systems, as they can represent significant vertical challenges or conduits for further exploration. Their formation is a slow, continuous process driven by the interaction of water and rock.