Its discovery occurred unintentionally on the afternoon of the 24th of December 1963, when five kids wandering the hill known as Cerro Romperropas or Cerro del Águila (Hill of the Eagle in English), were surprised to see steam coming out of a hole. The steam was produced by the difference in temperature in the caves, about 17°C, and the cold weather outside.

Helped by ropes and lanterns, the boys ventured into what appeared to be an animal’s hole, just 60cm in diameter. They descended for a while and crawled through about 50 or 60 meters until they reached the great main gallery. Afterwards, they were lost inside the caves for almost five hours, until they finally found the hole they came in from.

Then came everything else, giving the news of the great discovery to the authorities, the owners of the farm, experts, etc. After hard work of conditioning and since July the 18th 1964, Cuevas del Águila (Caves of the Eagle in English) are open to the public every day of the year.


The cave consists of a karst cavity formed by geological processes of thousands of years, such as rainwater filtering limestone and groundwater currents. The cave ceased to function as an underground conduction and since then, through extremely slow surface water seeping through cracks loaded with CO2 dissolve the calcium carbonate and create stalactites, stalagmites, pillars, flowstones and helictites, among other types of speleothems. It is estimated that a speleothem grows one centimeter every 150 years.


Thousands of years ago, due to settling, or washing away, of underlying sediment, numerous columns broke, many of which show a flat separation between the two pieces at mid-height.


The cave’s formation is composed of Paleozoic limestone attributed to the lower Cambrian. What does this mean? That they were formed between 500 and 540 million years ago. Imagine, when invertebrates like the Trilobites were the dominant animal species on earth.
Carretera Cuevas del Aguila, S/N,
05400 Arenas de San Pedro
Ávila, España
+34 920 37 71 07