Therma, situated 2 km east of the capital and celebrated since ancient times for its therapeutic radioenergic hot mineral springs, is the main spa town of Ikaria. It has a picturesque bay with a small inlet and a lovely beach for swimming. The white-washed houses, some lower others higher standing one next to the other with their flowery balconies, come into view only a few meters from the beach. All around are hills and in the distance on either side rise the rocks of the gorge at the mouth of which lies Therma. It is a secluded place overlooking the sea and on the waterfront all around the small square stand the traditional coffee shops, restaurants, and bakeries. Nearby you will find the springs and further down the road the newly built church of Agia Anargiri with its beautiful stained glass windows built in 1966 to satisfy the religious needs of the holiday makers. The village feast is held on the first of July, the day of Agia Anargiri. Therma has 3 of the principle hot springs on Ikaria. The hot springs aid in the curing of a multitude of afflictions such as rheumatism, arthritis, arthrology, neuralgia, and infertility.

Therma takes its name from the ancient Ikarian town of Thermae. In bygone days the inhabitants of Thermae were known as Asclipians from the god of medicine(Asclipios) and in recognition for their miracle working hot springs. At a small distance east of the present day town at the location Xalasmena Therma stand the ruins of the ancient spa. It was a seaside town built on a small projecting peninsula and was one of the known spas of ancient times. This is proven by the fragments of broken marble bath tubs found in the area and traces of an ancient aqueduct partly hollowed out in the rocks. Unfortunately it is not known exactly when this ancient town was inhabited. However, from a marble Stele found in the area we know that the town existed and flourished in the classical era and was a member of the Athenian Naval League. Its disappearance, probably due to an earthquake circa 205 B.C., did not allow for more information to come to the surface about the life of the Thermaen people. Although no archaeological research has been carried out it is believed that the seacoast where Xalasmena Thermae is situated is the exact location of the ancient city of Thermae.