Step inside Spain's glittering mountain of salt
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From a distance, Muntanya de Sal looks like any other mountain. But then you head to its base and it’s clear that it’s completely different from any other peak in Europe. Muntanya de Sal is made of salt. It is unlike other outcroppings piercing through the rolling landscape.
It is in the village of Cardona, Spain. That is about 60 miles northwest of Barcelona. Muntanya de Sal is also called Salt Mountain. It has been an important resource for the people residing in the area over the centuries. Locals removed salt from the surface. They used it as a commodity. The earliest evidence occurred sometime during the Neolithic period (approximately 10,000 BCE). That is according to historians.
“Later the Iberians, the Romans, people [living during] the Middle Ages and so on kept doing the same,” said Montse Malavé.
Malavé is a historian with Fundación Cardona Histórica. It is an organization that protects and preserves the town’s historical heritage.
“Salt was so valuable that at certain times it was even used as currency. People would go to the marketplace and could pay using a piece of salt. This mountain was like a mountain of money. Salt was called ‘the white gold.’”
Salt Mountain Cultural Park tops out at just under 400 feet in height. It is one of the highest points in the region. But about 40 million years ago, the area was completely underwater. It was engulfed by the Cantabrian Sea, according to Malavé.
“As time passed, the entrance in the north got closed and this part of the sea became a lake. It eventually dried out and great amounts of salt were precipitated to the bottom in horizontal layers,” he says.
“At the end of this process, the salt layers were covered by sediment. This happened all along the land that was covered by the sea. But the only place where the salt appeared on the surface is here in Cardona. This happened due to strong [upward] pressure in the Pyrenees mountains zone. It was a consequence of the crash between two tectonic plates.”
The Pyrenees mountain range formed approximately two million years ago. The underground salt layers were pressed and folded. And they pushed upwards. This formed a fold of salt underground. The top layer was made of sediment. It became thin thanks to erosion. This forced salt to crystallize at the surface. Interestingly, the mountain continues to grow in height. This is a result of the consistent pressure occurring below the surface. It is one of the few places on the planet where salt deposits sit both underground and on the surface.
From 1929 to 1990, Salt Mountain was one of the world’s largest mines for potassium chloride. It is a metal halide salt sought out by a wealth of industries. These include agriculture and medicine. It also incldues food processing.
The remaining salt deposit stretches approximately one mile in depth and has a similar length. The former mining complex has become a popular tourist destination. Today the cultural park offers guided one-hour tours inside the mountain’s depths. Visitors can walk through tunnels punctuated with sparkling salt stalactites. They also have stalagmites and columns.
“The salt walls are in pink/reddish, gray and white colors,” Malavé says. “Visitors are completely surrounded by salt.”