Furnas is a small town in the volcanic interior of São Miguel, with two main draws: the volcanic activity and the botanical garden.
The geothermal area is best seen at Lagoa das Furnas, a few kilometres southwest of town. The smell of sulphur is heavy, and small fumaroles of bubbling, boiling water hiss from the ground along the lake shore. Some of these natural vents are used for cooking cozido das Furnas — a traditional stew slow-cooked underground in volcanic heat, then served at restaurants in the town centre. A good walk starts at the southern end of the lake (near the Capela de Nossa Senhora das Vitórias), follows the western shore to the fumarole area, and continues on a trail back into town.
The Terra Nostra Garden, founded around 200 years ago by the American Thomas Hickling, is one of the finest botanical gardens in the Azores. At its centre is a large pool of warm, iron-rich thermal water — the rejuvenating properties are much advertised, though the yellowish-brown colour takes some getting used to. In the village itself, the Caldeiras da Vila bring the boiling springs right into the centre, and the smaller Poça da Dona Beija thermal pools stay open until late evening.