Have you ever stepped into a natural hot spring built on the side of an active volcano? Termas Geometricas are the most impressive hot springs I have ever been to. With a Japanese design and a Swiss chalet inspired restaurant, Termas Geometricas are built on Villarica Volcano, inside a canyon hidden in the forest, alongside a rushing stream crossed by waterfalls. There are 17 pools of natural hot water with temperatures between 35 and 45 degrees. It is best visited by night, when the outside temperatures are low.