Hot Thermal Sources
The abundant hot springs are another special feature of Nisyros. At many points along the coast of the island, hot water flows at temperatures ranging from 30 to 61 degrees. It involves mixing sea and rain water with the geothermal fluids of the upper hot horizon. These, warm and lighter, manage to reach the surface following the great cracks and cracks in the area.
The most famous of the hot springs are those of Loutra, 1500 meters north of Mandraki, and Thermiani, next to the church of Panagia Thermiani, at the northern edge of the village of Palon. Both are classified as 'thermal hydrosulfurized algae'.
The source of Thermia is known from antiquity. The inscription found in the ruins of the large portico of Roman baths operating in the same area «Ολβιος άνερ ός κατ’ ελάινον ουδόν Ιπποκράτους βαλανείων νοσειρών νόσων ώδ’ έσσεται» (Happy the man who will do so, will soon see the merciful (oak-tree) threshold of Hippocrates' baths [rinsing] the harmful diseases) reinforces the view that the Hippocratic medicine father had chosen the source That of Nisyros as a healing spa center. In the same source, Buondelmonti is probably mentioned as a thermal bath:
Ad trionem in pede montis, contigua maris, spelunca consistit, ad quam circumstantes, doloribus oppressi, accedunt, et, diu morati, in patriam incolumes reventuntur
On the nearby coast, on the outskirts of the mountain, there is a cave where sufferers of pain come to heal, stay for a while and then leave healthy.
The last period of operation of the treatment center in the area is from 1895 until the beginning of the 1930s, known as "Loutra Pantelidis".
Today, the old baths have been restored, but they are not yet ready to work. The source temperature is 33 degrees, but it is expected to increase by 8-10 degrees if the water is pumped.
The waters of the hot spring of Loutra have been taking advantage of the Municipal Baths of Mandraki since 1872. Its therapeutic properties are known for rheumatism, arthropathies, skin diseases and circulatory system diseases. The maximum source temperature is 46 degrees.
A third well-known hot spring is in the bay of Avlaki. Its waters had been used for bathing before abandoning the settlement. The hot water is gushing today in the sea and its maximum temperature is 61 degrees.
In addition to hot springs, there are many places in Nisyros where hot steam rises. Two of these places were used in the past as natural saunas. The main one, known from antiquity, is in the place of "Piria", where the chamber of the steam baths and adjoining auxiliary baths is still preserved. The other location is at the entrance of Emborios settlement. The vapor temperature is 34-35 ° C.