Even though the existence of groundwater all throughout the Province of Entre R?os was widely known, it was after the construction of Salto Grande Hydroelectric Dam, on the Uruguay River, that the first drill works let these "healing waters" out.This hot groundwater, mentioned by all workers in the dam construction site at first and thrown into oblivion shortly afterwards, would become the tourist hope of many cities lying on the banks of the Uruguay and Paran? Rivers years later. These locations were longing for a "new attraction" capable of luring visitors year round.The first of Entre R?os hot springs was Federaci?n, which still makes its denizens feel proud. As a result of the discovery of its hot spring waters, this city found a way of coming back to life after the old shell was flooded by the great lake.Thus, cities like Chajar? (with natural cascades and pools), Concordia (with mineral and drinking water), Col?n (ideal waters to be drunk before breakfast and to fight gastric disorders), Concepci?n del Uruguay (perfect to be enjoyed until the night falls), Villa Elisa (with salt waters), and carnival-loving Gualeguaych? (the closest to the Federal District) joined the Uruguay River Corridor.
