The thermal pool at Terra Nostra Garden in Furnas, Sao Miguel, doesn’t look particularly appealing at first sight. But don’t let the murky brown colour put you off – it comes from the iron dissolved in the water gushing from a volcanic spring at 35C to 40C, the perfect temperature to ease sore limbs after a strenuous hike.
Such springs dot these islands, but the Valley of Furnas is a hotspot of geological activity even by rarefied Azorean standards. The valley, which is in fact a huge volcanic crater, first became popular in the 18th century thanks to growing interest in the healing power of the mineral-infused water.
There are several other places where you can bath in Furnas, but the pool at Terra Nostra is the largest and most famous option; built in 1780 by a wealthy American expat and enlarged in 1935, it forms the centrepiece of a sublime subtropical garden, which all adds up to a profoundly restorative experience.