Relaxing Day at Santa Teresa Thermal Waters. Do you know the biggest ausol in Central América? Discover it at Santa Teresa Thermal Waters, a touristic attraction in the region of Ahuachapán, perfect for a relaxing and leisurely day. Its thirty thermal water pools promise relaxation and make you feel rejuvenated. Many people claim these thermal waters have curative powers; you can feel the warm sensation throughout your body and feel the energetic effects of this water that sprouts from the depths of the earth. Book with us and Save 82%! Relaxing Day at Santa Teresa Thermal Waters.