Overview of hydrogeothermics in Spain

Hydrothermic features in Spain have been used since ancient times for therapeutic purposes. At present, the number of spas has decreased notably, although some of them have been restored for aesthetic reasons. From 1970 onwards hydrogeothermic energy started to be used. There are some boreholes and small facilities at several places in Spain, mostly on the Mediterranean coast and near Madrid. The hydrochemistry of spanish thermal groundwaters is directly related to the geological nature of granite and limestones where most important springs are located.