Buzz
Just five years after Marie Curie’s discovery of radium, another prominent scientist, J. J. Thomson, wrote to Nature magazine detailing his research on the radioactivity found in well water. Soon after, the magazine published a study showing the radioactivity in various mineral waters, with some of the most famous baths testing positive for natural radioactivity, which was attributed to radium traces in the rocks the water flowed through.
Not long afterward, the health industry began to take notice of this discovery. Radium salt in bath water was proposed as an experimental treatment for ailments like gout, arthritis, and neuralgia. The development of more efficient methods for extracting radium from pitchblende in 1913 paved the way for the commercialization of these treatments, marking the beginning of a golden age in radiation therapy.
Today, particularly after the Chernobyl and Fukushima disasters, and the bombings of Hiroshima and Nagasaki, we are extremely cautious about any exposure to radiation. However, the truth is, we are all exposed to it daily. The International Atomic Energy Agency reports that normal radiation exposure from sources like the Sun, cars, CT scans, and X-rays totals 2,400 microsieverts per year.
Choosing to take radium baths is a personal decision, but the reality is that people from all over the world have been using them long before anyone understood radiation—long before the disasters or the phenomenon known as 'radium fever'—and they remain popular today in many parts of the world.
So, if you decide to take a dip in one of these baths, where can you find them?
10. Jachymov Spa, Czech Republic
Situated in northwestern Bohemia, Czech Republic, Jachymov holds the title of the world’s oldest radon spa, established in 1906. Each year, approximately 20,000 visitors come here. Bathing sessions are strictly regulated, with every participant receiving an exposure of millisieverts of radiation throughout their three-week treatment.
However, Jachymov’s significance dates back much earlier, to the 16th century when local miners first discovered silver in the mineral-rich Ore Mountain Valley. Later, immigrants from Saxony renamed the area Sankt Joachimsthal, a name derived from the German word thal, meaning “valley.” The coins minted here became known as “Thalers,” which later gave rise to the term “dollar.” Joachimsthal is also home to the world’s oldest uranium mine—the Svornost (Concord) pit. Initially a silver mine, it later became a source of uranium ore and is now where the radon water used at Jachymov spa is sourced before being transported to the city's numerous baths through a system of pipelines.
It was within the pitchblende ore from Joachimsthal that Marie Curie first discovered radium, the groundbreaking achievement for which she later won the Nobel Prize.
9. Milk River Mineral Bath, Jamaica
The Milk River Mineral Bath is named after the nearby river, which unfortunately is home to crocodiles, making it unsuitable for swimming. The waters in these baths are claimed to be 54 times more radioactive than those in Baden, Switzerland, and three times more than in Karlsbad, Austria. Located in the basement of the Milk River Hotel, the baths offer six private rooms, each with its own bath. It is recommended to soak for 15 minutes, with no more than three sessions per day.
Local legend tells that in the 18th century, a runaway slave discovered the radioactive spring. After being beaten and whipped, he soaked in the spring’s healing waters. When he returned to the plantation healthier in just a few days, the owner promised him forgiveness in exchange for the location of the remarkable spring. The owner then constructed a bath at the site, and after his passing, it was left for the public to enjoy.
8. Rudas Bath, Budapest, Hungary
Budapest is often referred to as the world’s bath capital, but one in particular stands out due to its slightly radioactive waters and historical charm: Rudas Bath. Built in 1550 and later reconstructed in 1566 by Pasha Sokoli Mustafa on the Buda side of the city, Rudas was originally established as a Turkish bath during the Ottoman rule in Budapest.
The centerpiece of the spa is a 10-meter (30 ft) dome, adorned with star-shaped openings and filled with colored glass, supported by eight pillars, with an octagonal pool beneath it. Surrounding this are smaller dome-covered pools, each containing slightly radioactive water at different temperatures. A drinking hall offers spring water, which is valued for its health benefits. Additionally, as a traditional Turkish bath, the spa maintains separate days for men or women.
However, not everything at Rudas Bath is about relaxation. In 1998, Cinetrip, led by artistic director Laszlo Laki, hosted their first “sparty” here. Combining international DJs playing electronic music, lasers, belly dancers, silent films, and the historic ambiance of the Turkish baths, the event quickly became popular not just with locals, but with international visitors as well.
7. Laghetto di Fanghi Mud Bath, Vulcano Island, Italy
Although less famous than Etna, Vesuvius, or Stromboli, Vulcano Island is renowned for its radioactive mud baths. The Laghetti di Fanghi are thick and pungent, but they are highly regarded by Italians for their health benefits. To experience them, visit the tiny Vulcano Island, covering just 21 square kilometers (8 mi), located around 25 kilometers (16 mi) north of Sicily's coast.
In addition to soaking in the muddy waters, you can also coat your entire body in the mud and use it as a mask. Be prepared for the intense sulfur smell, which many people find unpleasant. It’s also important to leave any jewelry or watches behind—the mud damages them. The mud can also ruin clothes, so don’t wear your best bathing suit. As with all radioactive springs, it’s recommended not to stay submerged for more than 15 minutes.
6. Cleopatra’s Pool, Pamukkale, Turkey
Pamukkale is famous for its white terraces, but it’s also home to the ancient city of Hierapolis, which is over 2,000 years old. A UNESCO World Heritage Site, it was established as a thermal spa by the Attalid dynasty, rulers of Pergamon. Used for washing and drying wool, it was later acquired by the Romans in 129 BC. It then grew into a thriving cosmopolitan city, where Anatolians, Graeco-Macedonians, Romans, and Jews coexisted.
Much like it was a popular health destination thousands of years ago, with pools, hot basins, and other facilities designed for thermal water enjoyment, Pamukkale still attracts visitors from across the globe. The ancient baths have been reopened to the public, and one of the last remaining untouched hot springs was recently transformed into Cleopatra’s Pool. Known also as the Sacred Pool, this is special for its radioactive waters. For a fee, you can swim among ancient Roman columns and other ruins that collapsed during a seventh-century earthquake. Alternatively, you can wander around the site for free and enjoy the stunning views.
5. Ramsar, Iran
Situated in northern Iran along the Caspian Sea coast, Ramsar is famous for having the highest natural background radiation on the planet, reaching up to 260 millisieverts per year. This is partly due to radium-226 being dissolved by underground water, which is then carried up through hot springs and used in local baths. While not widely known internationally, these baths are quite popular in Iran.
A standout feature in Ramsar is a black water sulfur spring located in the eastern part of the city. This spring is cooler than other similar sources in the area and is quite active, with uranium levels ranging from 5 to 11 parts per million. If you’re in the vicinity, it's also worth stopping by the vacation palace of the last Shah, Mohammad-Reza Pahlavi, which now houses the Caspian Museum, affectionately called “Tamashagah Khazar” by locals. Nearby is the Old Hotel Ramsar, located at the base of the mountain. Built in 1934, this palace boasts 25 rooms and five royal suites.
4. Ikaria, Greece
Contrary to popular belief that its name comes from the myth of Icarus, it is more likely derived from the Phoenician word for fish: ikor. This Greek island is renowned for its abundant hot springs. It has been inhabited since the Neolithic era and is frequently mentioned in ancient texts for its wild seas and famed wine.
Up until the late 1950s, Ikaria was overshadowed by Greece's more famous hot springs. Even today, it remains far from a typical tourist hotspot. However, if you’re willing to explore, there’s something for everyone. For the more cautious, you can visit the mildly radioactive springs in Lefkada. For a stronger experience, make your way to Therma, home to some of the most radioactive springs in the world, including Mustafa, Kratsa, Apollon, and Artemis, all of which have been known since antiquity.
While in Therma, don’t miss the opportunity to explore the ruins of the original ancient spa town. Likely buried by an earthquake, the remains of its acropolis and spa facilities were uncovered and are now open for tourists.
3. Ladek Zdroj, Poland
Nestled in southwestern Poland, the homeland of Marie Curie, Ladek Zdroj is one of the country’s oldest health resorts. The earliest mention of local bathing practices dates back to 1325, as recorded in the Klodzko Chronicle. By the 16th century, the town already had a bathhouse and established regulations for its use.
The real boom for Ladek Zdroj began in the 19th century, when numerous spas were constructed, including the remarkable “Wojciech,” which blends Turkish bath influences with a Roman-style pump room. Still in operation today, it’s definitely worth visiting, especially for its 17th-century round swimming pool, made from marble and topped with a Neo-Baroque dome.
The healing waters of Ladek Zdroj come from six naturally flowing springs and one borehole. Renowned for their curative properties, these local baths have been frequented by many notable visitors, such as Johann Wolfgang von Goethe, Tsarina Catherine II, Emperor Alexander I, and U.S. President John Quincy Adams.
2. Misasa Onsen, Japan
The tradition of bathing in hot springs, known as onsens, has been deeply ingrained in Japan for centuries, with about 270 of them containing mild levels of radioactivity. What’s perhaps unexpected to outsiders is that, even after the Fukushima and Nagasaki tragedies, their popularity remains unchanged. Misasa Onsen is one of Japan’s most renowned radium baths and, without a doubt, one of the most radioactive. Its name, Misasa, literally translates to “three mornings”—the believed time it takes for the hot springs to cure you.
The outdoor public bath, known as “Kawara-buro,” serves as the symbol of Misasa hot springs, located right beside the Misasa River. Another unique attraction is a hot spring nestled under an ancient camphor tree, with a public bath built around it, called “Kabu-yu.” Additionally, every August, the city holds the Marie Curie festival to honor the woman who discovered radium.
1. Hot Springs, Arkansas, United States
Undoubtedly the most famous hot springs in the United States, these springs were so highly esteemed that in 1832, Congress established the first federal reservation for the area, which later became part of the national park system. The healing properties of these baths were even recognized by the military, which opened the Army and Navy General Hospital here in 1879. However, Native Americans had known about the springs long before that, referring to the area as the “valley of the vapors.”
At the dawn of the 20th century, during the “radium fever,” the healing properties of the waters were believed to stem from radium, and the equipment in the baths was designed to maximize the retention of radon gas. Today, the approach has changed, with efforts now focused on allowing the gas to escape. The entire area of “Bathhouse Row” is now designated as a National Historic Landmark District, but if you’re interested in taking a bath, two of the bathhouses—Buckstaff and Quapaw—are still in operation.
