Thermal Hot Springs
Abundant hot springs are another special feature of Nisyros. In many places along the coast of the island hot water gushes, at temperatures ranging from 30 to 61 degrees. It is a mixture of sea and rain water with the geothermal fluids of the upper hot horizon. These, as warm and lighter, manage to reach close to the surface following the large cracks and crevices in the area.
The best known of the hot springs are those of Loutron, 1500 meters north of Mandraki, and Thermiani, next to the church of Panagia Thermiani, at the northern end of the village of Palos. Both are classified as "thermal hydrogen sulfide aliphates".
The source of Thermiani has been known since antiquity. The inscription found in the ruins of the large portico of the Roman baths which operated in the same area "Olbian man by no means Hippocrates of Valania's disease's disease" (Happy man who will become like this (will be healed), [just passes ] the poor (olive wood) threshold of Hippocrates's baths [which wash away] harmful diseases), reinforces the view that the father of medicine Hippocrates had chosen this spring of Nisyros as a thermal spa. The same source probably mentions Buondelmonti as thermal baths:
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 shore, on the edge of the mountain, there is a cave where those who suffer from pain come to be healed, stay for a while and then leave healthy.
The last period during which a therapeutic center operates in the area is from 1895 until the beginning of the 30's, the well-known "Loutra Pantelidi".
Today the old baths have been restored, but they are not yet ready to operate. The temperature of the spring 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 exploited by the Municipal Baths of Mandraki since 1872. Is It is famous for its healing properties in rheumatism, arthritis, skin diseases and diseases of the circulatory system. The maximum temperature of the source is 46 degrees.
A third known hot spring is the one in its bay Groove. Its waters had been used for bath therapy before leaving the settlement. The hot water is gushing in the sea today and its maximum temperature is 61 degrees.
Apart from the hot springs, in Nisyros there are many places where hot steam emerges. Two of these sites have been used in the past as natural saunas. The main one, and known since antiquity, is in place Fireplaces, where the steam bath chamber is still preserved and adjacent buildings of the baths. The other place is located at the entrance of the settlement Emporios. The temperature of the vapors is 34-35 ° C.