Fuentes Georginas is a superb natural spa in a spectacular setting, an 8km drive uphill from Zunil. Four pools of varying temperatures are fed by hot sulfur springs and framed by a steep, high wall of tropical vines, ferns and flowers. Though the setting is intensely tropical, the mountain air currents keep it deliciously cool through the day. Bring a bathing suit.
There is a second spa annexe a 10-minute walk further on from the main spa, with wooden changing huts.