Speleology, the scientific study of caves, draws explorers to challenging environments on Earth. Expeditions penetrate the planet’s vertical void, pushing the limits of human endurance and technology. Subterranean systems are measured by a specific metric that defines their scale. This article explores the definition of “deepest” and reveals the five known caves that plunge farthest into the Earth’s crust.
How Cave Depth is Measured
The term “deepest cave” refers to the maximum vertical extent of a cave system, not its total surveyed passage length. This measure is the difference in elevation between the highest accessible entrance and the lowest explored point within the cave. This vertical drop is the standardized metric used by the speleological community to rank the world’s deepest systems.
To determine this distance accurately, explorers use a meticulous process of surveying and mapping. Traditional methods involve using a compass for direction, a clinometer for inclination, and a tape measure for distance between fixed stations. Modern expeditions frequently employ digital measuring devices and laser rangefinders, which improve data precision. These measurements are plotted to create a comprehensive three-dimensional map, revealing the true vertical separation from the surface to the cave’s bottom.
The Five Deepest Caves in the World
Veryovkina Cave
Veryovkina Cave, located in the Arabika Massif of the Gagra mountain range in Abkhazia, holds the title of the world’s deepest known cave. The system plunges to a depth of 2,212 meters (7,257 feet). Its entrance is deceptively small, measuring only about three by four meters, belying the complex vertical shaft system below. Russian speleologists confirmed this record depth in 2018, establishing it as the first cave to exceed 2,200 meters. It is named in honor of Alexander Verëvkin, a cave diver who died in a nearby cave in 1983.
Krubera-Voronja Cave
Until Veryovkina’s depth was confirmed, Krubera-Voronja Cave was the world’s deepest, and it remains one of only two systems exceeding two kilometers in depth. Situated in the same Abkhazia region, this cave reaches a depth of 2,199 meters (7,215 feet). Krubera is often called the “Cave of the Crows” and is known for its hydrological complexity. Explorers discovered a species of springtail, a tiny invertebrate, living at a depth of 1,980 meters, establishing a record for the deepest terrestrial animal ever found.
Sarma Cave
Sarma Cave is the third deepest in the world, also situated in the Arabika Massif in Abkhazia. This system descends to a depth of 1,830 meters (6,004 feet). Discovered in 1990, the cave features a complex network of chambers and passages connected by numerous vertical drops. Sarma’s hydrological features are noteworthy, with vast amounts of water flowing through the system, often turning into dangerous torrents during high precipitation.
Snezhnaya Cave
Snezhnaya Cave, which translates to “Snowy Cave,” is the fourth deepest at 1,760 meters (5,774 feet). It is the last of the four deepest systems located in the Abkhazia region. This cave is known for its extensive underground river network and impressive ice formations near its entrance. The system contains two of the largest underground chambers in the region, the Throne Hall and Hall X, with the latter featuring a ceiling height of 50 meters. The cave is a major focus for speleological research.
Lamprechtsofen
Lamprechtsofen, the fifth deepest cave in the world, is located in the Leogang Mountains of Salzburg, Austria. This system reaches a depth of 1,735 meters (5,692 feet) and is a rare example of a deep cave outside of the Caucasus region. Lamprechtsofen is one of the few deep caves with multiple entrances. Its deepest point was reached from a high-altitude entrance, and its vertical nature makes it challenging for cavers.
The Challenges of Deep Cave Exploration
Venturing into the world’s deepest caves requires overcoming physical and logistical hurdles. Explorers navigate intense cold and pervasive humidity, which increases the risk of hypothermia over multi-day expeditions. Communication is difficult, necessitating multiple subterranean base camps to stage equipment and allow cavers to rest.
The vertical nature of these systems demands complex rigging and ropework to safely descend and ascend hundreds of meters of drops. Water poses a threat, with passages often turning into sumps—water-filled sections requiring specialized scuba gear. Flash flooding is also a risk, as surface rain can quickly inundate lower sections.
Deep exploration carries the danger of encountering pockets of toxic gases, such as odorless carbon dioxide or methane. Disorientation is a risk in the labyrinthine passages, and the failure of a primary light source can quickly become a life-threatening emergency. The physical and psychological toll of isolation and exertion necessitates high levels of training and meticulous planning.