Ponta da Ferraria hot spring in São Miguel, Azores
Credit: Catarina Maia / Azores Getaways

On the westernmost point of São Miguel, the largest island in the Azores, lies a sulfurous hot spring that’s been used by swimmers and wellness tourists since the Portuguese first populated the archipelago in the 15th century.

This isn’t actually that unusual. As a volcanic island chain still bubbling and gurgling with geothermal activity, the Azores — and especially São Miguel — have always been known for hot springs and mineral water spas. What makes the hot springs at Ponta da Ferraria unique isn’t the temperature or the alleged healing powers of the water. It’s where the water comes from: the termas of Ferraria are in the ocean.

At Ferraria, the contours of São Miguel’s rocky western shore form a well-known piscina, or natural swimming pool, sheltered by basalt crags and fed by a set of hydrothermal vents.

It's claimed that the area’s highly unusual combination of saltwater and sulfurous spring water helps with any number of conditions, especially inflammatory concerns like arthritis. But visitors must pay careful attention to the day’s tide tables; when the water is at its highest, the hot spring flow has little impact on the ocean’s natural temperature (and the shape of the rock barrier can occasionally lead to dangerously rough waves). Some warn that, at the lowest tide, the water can be uncomfortably hot.

Portugal, Azores, Sao Miguel, Ponta da Ferraria, Pico das Camarinhas
Credit: Getty Images

Time it right, though, and the pool will be calm and warm, the cold water of the Atlantic mixing with the natural heat of the shoreline’s volcanic fissure to create perhaps the most remarkable thermal pool in all of the Azores.

Ferraria is also home to a number of rock climbing routes up the basalt cliffs overlooking the pool, where local tour operators like Azores Getaways offer guided climbing experiences to get your heart pumping before a relaxing swim. The warm water is also diverted to feed the private pools at the nearby Termas da Ferraria spa, which offers a lineup of relaxation treatments and a seafood-focused restaurant overlooking the ocean.