Salina Praid is a rock salt mine in Romania, located in Harghita County. The salt mine is located in the basin of the Gurghiului mountains, included in the Salt Hill, forming the triangle Praid – Ocna de Jos – Ocna de Sus.
The salt deposits in Transylvania (systematically exploited over time at Ocna Dejului, Sic, Cojocna, Turda, Ocna Mureș, Ocna Sibiului and Praid) were formed 13.5 million years ago, in a shallow sea and under a tropical climate, very hot. The respective geological floor corresponds to the Middle Miocene. The salt layer extends everywhere in the subsoil of Transylvania, having an average thickness (original) of about 400 m. The thick layers of sediments subsequently deposited above the salt horizon pressed with great weight the malleable and plastic layer of salt, which sought more areas. weak of the earth’s crust on the edge of Transylvania, where it rose in the form of mushrooms with heights of over 1,000 m, often reaching even to the surface of the earth (the case of localities with old salt mines mentioned above). The salt body from Praid has a slightly ellipsoidal shape in the horizontal plane, with diameters of 1.2 and 1.4 km, and based on the exploration probes (S ACEX 401/1949 and S 110/1973) it is estimated that it has a depth of 2.6 – 2.8 km, being in this way the largest diapirogenic body of rock salt in the country.
The first salt mines are attested from the time of the Romans, but the mine from Praid is documented from 1200, and the intensive exploitation is made from 1700. The Romans worked only on the surface, in quadrilateral pits, up to a depth of 12-15 m, from where the salt could be easily removed on slippery bridges and with simple lifting devices, after which they left it and started another. This is how the Romans extracted salt everywhere in Transylvania, and the abandoned excavations became lakes.
Volker Wollmann in his monograph on mining emphasizes the presence in the immediate vicinity of salt deposits, each time, a Roman fortification. The Roman camp Praetoria Augusta from Inlăceni defended the salt mines from Praid.
In 1980, a treatment base was opened in the salt mine.
Following the extraction of the salt, large underground voids were formed, where a saline microclimate was individualized, with relatively constant temperatures, between 14-16 C, low humidity 66-70% and higher atmospheric pressure than at the surface, in average of 735-738 mmHg. The air is strongly ionized, particularly effective in treating respiratory diseases. The treatment base, located on the “horizon 50”, at a depth of 120 m, has a width of 20 m, a height of 14 m and a length of several hundred meters. At a distance of 1250 m from the entrance to the salt mine to the treatment base, the transport of people is done by the salt mine buses. The salt mine is equipped with recreation areas, playgrounds for children, restaurant, toilets, chapel for prayer, internet cafe and a museum that presents the methods of extracting salt from ancient times to today.
In the Praid salt mine, an underground speleological and climatotherapeutic treatment is performed, as a simple and effective method to improve the condition of patients suffering from respiratory diseases, to maintain and restore the balance of the soul and the tone of the vegetative nervous system.
In 2009, the Praid salt mine was the most visited salt mine in Romania, with over 200,000 tourists annually, followed by Slănic Prahova, with over 150,000 tourists and the Târgu Ocna Salt Mine and the Cacica Salt Mine.
Salt mine mining works
The underground exploitation of the rock salt from Praid began in 1762, when, in the southwestern part of the Salt Hill, the Iosif (József) mine was opened. The mine had a bell shape (ogival). The salt extracted by hand was put into buffalo skins and pulled to the surface with the help of a horse sieve.
Surface mines (quarries) are mentioned in 1765, they operated for a time in parallel with underground extraction.
One can speak of a systematic mining in Praid only from 1787, when the salt from Praid became the property of the Austrian state.
From the bell tower Iosif then opened two side chambers, called the mines Carol (Károly) and Ferdinand, in the shape of a bell. The total depth, including the extraction well, was 66 m.
In 1864, near the Iosif mine, the Parallel mine (Párhuzamos) was opened, with a trapezoidal profile, which is still one of the largest underground cavities in the country. The Church of St. Michael in Cluj would fit without problems in this room.
František Pošepný reported in detail about the active or inactive salt mines at Salina Praid in 1867.
In 1896, a single salt mine was opened in Praid.
The idea of opening a reserve mine appeared in 1898, when work began on the Elisabeta (Erzsébet) research gallery in the northeastern part of Salt Hill. From the Elisabeta gallery, several side galleries were drawn, researching the upper part of the deposit. 200 m from the entrance to the gallery, a transversal mining chamber was built, called the Elisabeta mine (Erzsébet).
Between 1947 and 1949, the Gh. Doja mine (Dózsa György) was opened, named after the leader of the 1514 peasant uprising.
After the horse-drawn carriage, the transport of salt from the mine to the surface was done through the Gh. Doja well and on the narrow railway, and after the 70s of the twentieth century, with 16-ton dump trucks.
In 1978, at a depth of 40 m below the level of the old mines, another mine was opened, put into operation in 1980. The chambers of the mine have widths of 20 m, heights of 12 m and lengths of several hundred meters. The deepest horizon is 320 m (calculated from the surface level).
In 1991, work began on opening a new mining sector (the Telegdy sector), put into operation in 1994. This sector was named after Telárdy Károly, former director of the Praid Salt Mine. The method of operation in the Telegdy mine is with small chambers and square pillars (the “Canadian method”) with widths of 16 m, heights of 8 m and square pillars (14 m x 14 m). The safety floor between the horizons is 8 m thick.
Tourism and speleotherapy
The speleotherapy and climatotherapy treatment practically includes inhaling the air from the mine, being very useful in case of respiratory diseases (asthmatic, bronchial and allergic diseases). The duration of treatment is 18 days. This underground treatment takes place at the “50” horizon, located at a depth of 120m from the surface. During the time spent underground, gymnastics led by a specialized staff, walks and dosing of physical effort are also recommended. The age category between which people can be treated is between 2-60 years, they are constantly supervised by a medical staff. According to the statistics of the specialist doctor from the commune, it can be observed that in the case of those who return to treatment 3-4 times and react positively, the number and intensity of asthmatic crises decreases and the body’s resistance capacity increases. Famous for the healing effects that the salt air has on the body, the mine looks like a small town located at a depth of 120 meters, in the heart of the mountain. However, not everyone comes to Praid for treatment, but many are attracted by the beauty of a mine that has a tourist destination for over 35 years. The beauty and uniqueness attract groups of tourists from all over Europe. Every morning the area at the entrance to the mine suddenly comes alive. Patients arriving for treatment, but also tourists crowd into the buses that go down a kilometer and a half in the heart of the earth. After the bus trip, access is on foot, 250 steep steps being a test of endurance especially for the elderly. Once in the salt mine, they all forget about the effort and integrate it as in a huge puzzle board in the arranged enclosure. Equipped with hundreds of wooden tables and sofas, a buffet, many children’s playgrounds, a small wooden church, pool tables and even an internet cafe, the underground halls receive up to 3,000 visitors a day during the peak season. . Tourists, but also patients come to treat especially respiratory diseases such as asthma, bronchitis and allergies. Praid salt mine is also the location with the first adventure park in Europe (Club Aventura), located in a salt mine. Club Aventura is also the first adventure park in Romania, which combines the routes with elements between poles up to 15 meters high and the routes on the salt rock. Wikipedia