Across Spain, countless caves regularly amaze travelers. Examples include the caves of Nerja, the Gruta de las Maravillas, or the caves of Altamira. However, nestled in the Spanish Pyrenees is a particularly extraordinary specimen: a frozen cave at high altitude.
Hidden in the Ordesa and Monte Perdido National Park in Aragón lies this unique natural attraction. It’s the Casteret ice cave, featuring unique ice formations and an underground glacier, making it one of the most remarkable natural phenomena in the Spanish Pyrenees.
Features of the cave
Situated at over 2,700 meters, the ice cave is one of the highest ice caves worldwide. The cave is named after the French speleologist Norbert Casteret, who discovered it in 1926. Casteret, a pioneer in speleology, encountered the cave during his explorations in the Pyrenees. The cave was already known to local shepherds by the name ‘Espluca Negra’. However, it was Casteret who first informed the scientific community of its existence. The constant low temperatures inside the cave ensure that the ice remains year-round, even during the warm Spanish summers.
Juan Ramón Rioja Alvarez – Google
Ice formations inside the cave
The Cueva Helada de Casteret is renowned for its ice stalactites and stalagmites. In several chambers and passages, temperatures remain around or just below freezing point throughout the year. These constant cold temperatures are crucial for the preservation of the ice formations inside the cave. The formation of ice stalactites and stalagmites occurs when meltwater from the cave walls freezes before reaching the ground. Over time, these processes create spectacular ice columns and structures that contribute to the cave’s unique and alien landscape. A significant feature of the cave is the presence of an underground glacier, complete with an extensive frozen lake.
Access to the cave
The Spanish authorities have taken measures to preserve the delicate ecosystem of the cave, closing it to prevent unauthorized access. However, visitors can undertake various hiking routes to explore the cave’s surroundings. These routes vary in difficulty and length. Different options include:
- From Pradera de Ordesa. It is the fastest way to reach the entrance of the Casteret ice cave.
- From Pradera de Ordesa, via the Góriz refuge. Pass some of the most beautiful spots in the Pyrenees, such as the Gradas de Soaso and the Cola de Caballo.
- From Gavarnie, through the Sarradets refuge. It is quite long and is a route that begins in the French part of the Pyrenees.
Scientific value
The ice cave offers scientists valuable insights into the region’s climate history. By studying ice cores from the cave, researchers can analyze the air bubbles trapped in the ice to reconstruct the atmosphere’s composition from the past. This data is essential for understanding climate change and the historical climate patterns in the Pyrenees and beyond.
Microclimates
Within the icy walls of the Cueva Helada de Casteret lie rare microclimates home to unique microbial communities, adapted to the cave’s extremely cold and stable conditions. These extremophiles, found nowhere else in the world, provide scientists with valuable insights into the possibilities of life under extreme conditions. Their adaptability to the cold, dark environment may even shed light on the study of astrobiology, by providing clues on how life could thrive on other celestial bodies in the solar system.
Ordesa & Monte Perdido National Park
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The Ordesa y Monte Perdido National Park, located in the Aragonese Pyrenees, is renowned for its spectacular landscapes, including deep valleys, towering limestone cliffs, and lush forests. The biodiversity in this UNESCO World Heritage site is rich, with numerous species such as the ibex, bearded vultures, and marmots. The park is a paradise for nature lovers and adventurers, with a multitude of hiking trails leading past crystal-clear mountain streams, waterfalls, and the impressive Gavarnie Circle.
