Balneario de Urbión El Burgo

Balneario de Urbión at El Burgo de Osma in the Castilian Duero valley draws bicarbonate springs enjoyed within a long thermal tradition since at least the 18th century, with waters bottled commercially under the Solares brand. The spa sits in a well-preserved medieval cathedral city surrounded by the vast wheat fields and dramatic limestone gorges of Soria province — one of Spain's emptiest and most pristine territories. The nearby Urbión peaks, headwaters of the Duero River, and Laguna Negra glacial lake offer some of inland Spain's finest highland walking.