The Mortillano system is the second longest
karst
Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant ro ...
system in
Spain and one of the largest in
Europe, the sixth, with 146.5 km of galleries.
History
Explorations of the system began in the 1960s and were resumed in the 1990s. Since then, more than 20 inlets and eight underground rivers with a large number of small tributaries have been found.
References
See also
* List of longest caves
Caves of Cantabria
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