Termas de Copahue, Thermal spa complex at Andean mountain pass in Neuquén, Argentina.

Termas de Copahue is a thermal spa complex nestled at an Andean mountain pass in Neuquén at 2012 meters elevation. The facility features multiple lagoons filled with mineral-rich waters, sulfurous pools, and volcanic mud sources.

The spa is fed by the Copahue volcano, and access by Provincial Route 26 is open only from November to May because winter snow makes the road impassable. In 1999, during the last term of Governor Felipe Sapag, a geothermal well near the Las Mellizas lagoons was tapped to heat the streets with volcanic steam. The complex is run by the provincial government of Neuquén.

The spa is run by the provincial government of Neuquén and receives patients for medical treatment of skin conditions, rheumatism, arthritis, respiratory illnesses and celiac disease, with an operating capacity of 2,500 sessions a day. Bathers move between fixed installations for steam baths and sulfurous, ferruginous or Laguna Verde water, and mud and volcanic-water applications.

Access is limited to November through May due to severe winter conditions in the high Andes. Visitors should prepare for alpine weather and bring warm clothing, even though the hot waters offer immediate warmth.

The complex's pathways are heated by a geothermal system that extracts volcanic steam from nearby Las Mellizas lagoon. This practical innovation demonstrates how the site harnesses its natural heat beyond just the bathing areas.