Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
SoufreSulfuresSulfates
Termas das Caldeiras in Ribeira Grande on São Miguel Island, the Azores, is a thermal establishment built in the nineteenth century within the calderas of this volcanically active Atlantic archipelago, where geothermal energy heats both the land and the sea. The springs emerge from the interior of São Miguel, the largest island in the Azores, in a landscape of steaming fumaroles, hot mud pools, and vivid green crater lakes that testify to the island's ongoing volcanic vitality. Bathing at Caldeiras connects visitors to a tradition of geothermal wellness unique to this mid-Atlantic volcanic outpost of Portugal.
Insider tip — Termas das Caldeiras sits in the volcanic caldera of Furnas on Sao Miguel island, surrounded by bubbling mud pools, steaming fumaroles, and the distinctive eggy scent of hydrogen sulfide rising from the active geothermal field below. The thermal pools here are fed directly by fissures in the caldera floor, and the water temperature must be carefully managed by mixing with cold spring water. The valley floor contains a unique ecosystem of hydrothermal plants and the famous cozido das Furnas, a Portuguese stew slow-cooked underground in the volcanic heat. Visit the Caldeiras hot springs at dawn before the tourist coaches arrive to experience the surreal mist-covered landscape in relative solitude.
