Undersea hot springs are a wonderful solution to chilly weather and ordinary beaches.
Greece has a number of islands where thermal springs provide natural warm-water bathing. While the surrounding water and beaches may be cold, and winds can be daunting, the mineral-rich waters are soothing. Most of them are seaside overflows of hot springs, but a few occur offshore and can only be reached by boat.
One of the most widely-known thermal bathing areas is at Santorini, on the islet of Palea Kameni, where volcanic waters warm the sea, adjacent to a pleasant little beach called Agios Nikolaos Bay which even boasts a charming chapel. This is served by the boat tours in the caldera, though you may be able to get a local water taxi to take you there. When visiting from the tour boats, guests are usually given about a half hour of swimming time in the hot springs, and these require a swim through deep water to the shore area where the spring waters well up. This creates a change in the color of the water so it is easy to see where you need to go. On busy days, the distance you need to swim to reach the warm water increases as the tour boats pull up just outside the small harbor. If you are not a strong or confident swimmer, this may be a challenge. It may also be a challenge finding your boat - they may change position while you are swimming in the hot springs area. On a recent (2015) trip to the hot springs, several people ended up on the wrong oats, which can look identical, especially from the level of the water looking up. So pay attention - but usually, these situations can be sorted out by the boat captains without any problem, other than the possibility of another short swim to the right boat.
The often-neglected large island of Evvia (Euboea), within easy reach of Athens, offers an abundance of hot springs, including several which warm the sea. The Capri Hotel is happy to help patrons discover these gems.
On Ikaria (Icaria), part of the Sporades Islands, the ancient and well-named town of Therma still offers a hot rivulet draining into the sea, providing a pleasant swimming area. Follow the path behind the Agriolycos Pension to reach the waters. Be aware - as these are known as the most radioactive waters in Greece, not all the heat may be just from the temperature!
The island of Milos also has numerous places along the coast where warm waters run into the sea. Milos is at one of the most active geothermal fields on the planet, which is also evident from the bizarre geological formations found everywhere on the island.
For the opposite effect, consider a visit to Krioneri or Town Beach on the coast near Parga on the Greek mainland. There, underwater springs send up exceptionally cold water into the shoreline swimming area.
Looking for your own special spring? Any seaside town or village named "Therma" is a good place to start - the ancients loved finding hot water sources and usually would settle nearby and name the resulting village after the hot water. The same word, ayiasma, or sacred water, can refer to springs near churches (often originally close to temples) and to any natural source of hot water, even more of a seeming miracle in ancient times than it is today. More on Sacred Springs in Greece
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