In the Albanian caves, the worlds largest underground thermal lake has been discovered

Scientists have confirmed the existence of the worlds largest underground thermal lake in the karst caves of southern Albania. Neuron, as it has been named, remained hidden for millennia until 2020, when researchers came across the first traces of its existence. However, it was only four years later, thanks to modern technologies, that it was possible to measure it accurately and confirm the unique nature of the reservoir.

How big is Lake Neuron?

Measurements of the reservoir showed that it is 138 meters long and 42 meters wide. Its volume is approximately 8,335 cubic meters, which is roughly equivalent to 3.5 Olympic-sized swimming pools. The high water temperature suggests that geothermal processes are still active in this region.

How was the worlds largest underground thermal lake discovered?

It all began in 2020 when a Czech research team was exploring the difficult-to-access karst terrain in Albania. At some point, scientists noticed an unusual column of steam rising above the mountains. Analyses indicated that this could be a sign of hot springs existing beneath the Earth’s surface.

The first expedition reached a previously unknown cave, where they discovered the lake. Due to a lack of appropriate equipment, it was not possible to conduct precise measurements. It was only in 2024, using lidar scanners, that scientists created a three-dimensional model of the cave and the reservoir. The results confirmed that Neuron is the world’s largest known underground thermal lake, surpassing the previously recorded reservoir discovered in 2008 beneath the Turkish baths in Budapest.

What technologies enabled precise research?

The research team used lidar (Light Detection and Ranging), a laser scanning method that allows for the accurate mapping of hidden locations. Hydrogeological measurements determined the temperature and chemical composition of the water. A high level of mineralization was found, which may indicate a connection to an extensive underground geothermal system. The water originates from deeper layers, heated by the Earth’s internal heat, and then flows into the cave through a network of rock fissures.

What does the name of the lake refer to?

The name Neuron is a tribute to the Czech Neuron Foundation, which financially supported the research expedition. Thanks to this support, it was possible to conduct detailed analyses and confirm the size of the lake.

Lake Neuron as a new research laboratory

The discovery of Lake Neuron opens up new research opportunities, allowing for a better understanding of geothermal processes occurring beneath the Earth’s surface and their impact on the development of life in extreme conditions. The expedition leader, Marek Audy, has announced further studies that could provide groundbreaking information about the underground ecosystem and geological processes.

Scientists plan to examine the microorganisms inhabiting this isolated, geothermally heated environment and conduct further analyses of the karst cave structures in the region.

main photo: Neuron Foundation