It is an experience that only a an of active volcanic activity can offer. You can see bubbles of steam (small geysers) coming out from under your feet; you smell sulfur, the soil is hot when you touch it. Most tourist would taste corn cooked in the hot water of the springs and the local favorite, Cozida - a meat stew cooked in the ground for a few hours (those in our group who tasted it said that they live without it :-)) There are hot springs and at least 2 places where you can "swim" in the hot water. The Furnas lake is in a volcanic crater. Gary, our guide, is from these places and he still has relatives living here. We drove around the magnificent lake and stopped for a couple of minutes to have him chat with his uncle and other relatives. Then we went to one of the peak overlooking the calderas and the lakes. There is a white streak on the lake that we could not explain, till we were told that because the lake gets nutrients from the fertilizers used around it, there is a growing problem of algae. The locals are fighting it, including building a pipe that releases oxygen - the bubbles of which create this white stripe. We visited the Terra Nostra garden and the Poca de Dona Beija - both places when you can enjoy the hot springs.
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