During the development of the great Mediterranean civilizations, man started to have a deep and complex relationship with water. Ancient civilizations considered thermal waters as something supernatural for their mysterious origins. The link between man and water developed by the passing of time, to such an extent that it reached its highest expression of civilization and wealth in Rome’s magnificent thermal buildings. The impressive and ingenious Roman thermes are the result of a millenary experience. Imperial Rome was a metropolis with more than one million inhabitants who were very well conscious about the leading role played by water for the development of human activities. During the Empire, Rome was a city rich in water and with numerous aqueducts capable of carrying one million cubic metres of water per day.