Over the last 2.5 million years, nature has painstakingly sculpted the surface of the north coast of the main island of the Puerto Rican archipelago, creating an almost magical conglomerate of caves, hummocks, aquifers and underground rivers throughout the region known as the karst of Puerto Rico. --- Lee este artículo en español.
--- This karst - an important natural system - covers practically all the northern municipalities, from Loíza to Aguadilla, and is composed of multiple limestone formations that began to be deposited 23 million years ago, during a time when the entire area was submerged under the ocean and where a rich marine life abounded. It is the peculiar qualities of limestone rock that allow it to react chemically on contact with water, allowing the liquid to seep through its porous surface and slowly dissolve. As a result, surface rivers are scarce in this area and instead unerground water flows abound, which in turn create these impressive cave systems throughout the karst zone.
However, the richness of the area is not only geological, since, in addition to the 14 important caves identified in this complex natural system and the underground streams, there are some 550 different species of flora and fauna, including most of the endemic birds of Puerto Rico and all the species of bats of the archipelago. Likewise, fossil evidence of ancient species and human activity -pre-Columbian and modern times- can be found. As part of the underground water flows cr.