They are strewn across the island, close to the town of Mytilene and beyond. These mineral springs are mainly the manifestation of an acute endogenous volcanic activity eventuating in the Tertiary Period. The importance of these natural springs is illustrated in the writings of Xaverius Landerer, a German who visited Lesvos in 1845 and conducted studies on the therapeutic properties of the waters. He informs us that Galene also praised their virtues. Theophrastos of Eressos and Aristides Aelios further recount the significance of the mineral water springs of Lesvos.
Bottled water emits a yellowish sediment after a period of time, composed of iron hydroxide.
Notwithstanding the above - mentioned illnesses, the waters are recommended for the therapy of arteriosclerosis and hypertension, sciatica, backache, diseases of the nerves, lymphatism, spleen enlargement, cirrhosis, paralysis, periostitis and rachitis. The site of the spring and the peripheral area surrounding the Bay of Geras, also known as the bay o Ieras or the Bay of Olive Tress, is considered to be most advantageous. This particular location is believed to be the site of the temple o Hera, where ancient Lesvides participated in beauty pageant rituals. Apart from the previously mentioned ailments the spring waters are recommended for the cure of rheumatism, sciatica of the hip joint, chronic rheumatism, skin diseases of an arthritic nature, illnesses of the womb, intestinal diseases, bronchial diseases and more. Furthermore, small quantities of tepid water dot the area from which a salty efflorescence or a yellow residue remain after evaporation.