Termas Geométricas is, by general consensus, the most beautiful hot springs complex in Chile. Set in a deep glacial ravine south of Lago Calafquén, it consists of 20 pools of different sizes and temperatures, connected by 700 metres of red-painted timber walkways. The hot water steams against the cold mountain air, particularly atmospheric on overcast days or in light rain.
The springs are about 90 minutes from Pucón. The complex is designed with minimalist elegance — the architecture feels like an extension of the landscape rather than an imposition on it. Book in advance in January and February when it fills up entirely. Admission is around 25,000 Chilean pesos; there are changing facilities and a small café. Plan a full afternoon.