Ischia, an island of volcanic origin has been known for its hot springs since the dawn of civilisation: from Homer onwards, poets, geographers, historians, naturalists and doctors (Timaeus, Ephorus, Pliny the Elder, Strabo) often spoke of Ischia as having such interesting natural phenomena and at the same time frequent volcanic telluric manifestations.

Even today, due to the intense volcanic activity of the now extinct Epomeo (which, according to the most approximate estimates, is about 2.5 million years old) and submarine craters, the island now has about 103 hot springs and 69 fumaroles (cracks and holes in the craters that emit hot steam).