How much can a water drop do? A lot, it turns out: in the caves of Central and South America, there are mineral formations known as stalactites and stalagmites that form the interiors of thousands of caves. All of them have one thing in common: they have been formed by water dripping over thousands or even millions of years. Some of these formations even exist under water.
Stalactites are formations created by a precipitation of minerals. They usually hang from the cave’s ceiling and resemble large, complex icicle structures with pointed tips. Limestone stalactites — some of the more common and also the slowest to grow — usually gain less than 10 cm every 1,000 years. Some have been found to be more than 190,000 years old, according to radiometric dating. The world’s longest stalactite in the world is 27 feet long and is located in Jeita Grotto’s cavern in Lebanon.
Stalagmites rise from the floor of the cave, also the result of water drops from the ceiling. Most stalagmites have rounded or flattened tips. The tallest standalone stalagmite measuring some 220 feet is located in the San Martin Infierno cave in Cuba.
Stalactite cave formations begin with a single drop of water. Each drop contains minerals, and when it falls, it deposits the thinnest calcite ring. The next drop does the same - and so on, elongating the structure. When a stalactite and a stalagmite meet, they form a column, also known as a pillar.
An incredible site of ancient stalactites and stalagmites, the Huagapo Grotto in Peru’s Palcamayo Highlands is almost 2 miles long. Behind the 100-foot entrance, you may just find the largest cave in the world. The cave walls feature drawings that are believed to date back to between 6,000 and 10,000 BC.
“Huagapo” comes from the Quechua word that means “weeping cave” — named so for the many underground streams that form a waterfall on the hillside. You can walk almost 1,000 feet into the cave along a rocky ledge. Beyond that, you will need a guide and special equipment, as the water is extremely cold.
Gruta do Maquiné, Brazil
Gruta de Maquine is the oldest cave in Brazil with seven large chambers to explore, measuring a total of 2,130 linear feet of walkways. Sala das Columnas, the Room of Columns, is full of massive stalagmite formations that rise up to the dome. Other chambers contain formations that resemble animals or magical creatures. Nineteenth-century Danish paleontologist Peter Wilhelm Lund said: "My eyes have never seen anything more beautiful and magnificent in the domains of nature and art." In fact, it was in these caves that the fossils of both prehistoric animals such as mammoths were discovered alongside human bones, leading Lund to conclude that humans coexisted with prehistoric animals.
The Talgua Cave in Honduras has been named so because of the way light reflected from the calcite deposits that covered the skeletal remains found by archeologists. (To be clear on the misnomer: the skulls did not glow; the calcium deposits did.) Scientists believe that they have uncovered the funerary site that was created during the Maya Empire. The cave is best visited with a guide, and during the dry season, since the wet season makes the crawl holes impossible to explore.
The Venado Caves in Costa Rica’s Arenal Volcano National Park seem to have to all: waterfalls, a river running through it, secret tunnels, and mineral formations, not to mention that they are home to bats, spiders and monochrome frogs.
The Great Blue Hole is a giant sinkhole with a diameter of more than 1,000 feet off the coast of Belize that is visible from space. It features some of the world’s most interesting underwater stalactite structures that are believed to have formed as early as 153,000 years ago, and some as recently as 15,000 years ago. Made famous in 1971 by French explorer Jacques Cousteau, the Great Blue Hole is also part of the larger Belize Barrier Reef Reserve System, a UNESCO World Heritage Site. In addition to ancient stalactites, you might just run into the Caribbean reef shark or the midnight parrotfish here.
If you have ever thought of traveling to Mexico — or if you’ve been — then you’ve heard of the underwater worlds known as cenotes. Some cenotes are vertical shafts, and others are caves that are completely or partially underground. Dazzling with mineral formations, there are thousands of cenotes throughout the Yucatan Peninsula. There are likely thousands more, as the cave network has not been fully explored.
The word “cenote” comes from the Mayan word “d’zonot,” meaning an underwater chamber that holds permanent water. The Maya believed that the rain god Chaak lived in the cenotes, and to this day, some Maya farmers in the Yucatan pray to Chaak for rain.
Something as seemingly harmless as skin oil can forever alter the surface tension of a stalagmite and change the course of its growth. For a stalactite, skin oil — as well as dead skin cells and salt from sweat — can be transferred onto the formation, and interfere with the interaction of air and water, disrupting the new calcite formation.
Stalactites and stalagmites are extremely important to scientists, providing archeologists with insights into the Mayan landscapes, and climate scientists with information about sea level changes and climate fluctuations over time. Also, many theories exist about the origins of life on earth, and some scientists think that there’s a connection between mineral formations and bacteria. It is unclear whether inorganic crystallization — such as that found in stalactites and stalagmites — could have led to life, but it has not been discounted, either. It may just turn out that these magnificent structures are even more important than we thought.