Balneario de Elgorriaga Nature · Elgorriaga, Baztan-Bidasoa, Navarra In 1846, doctors Alejandro San Martín and Antonio Simonena identified the medicinal properties of the waters of Elgorriaga, sodium chloride waters with a mineral content among the highest in the world, used to treat rheumatic, skin, and circulatory ailments. The current complex, part of Imserso's social thermal-tourism program, has 48 double rooms, 15 single rooms, 9 junior suites, and 3 suites. propiedades identificadas en 1846 Photo: Frobles (CC BY-SA 3.0) What to see and do in Elgorriaga