This is a familiar sign that is seen in and around the town of Furnas in São Miguel. Furnas is somewhat centrally located on the island and is home to many "calderas" or hot springs. The hot springs can be either sulfur or iron based.
You know you are approaching the town when you start to see misty clouds, steam coming out of the ground and when you sniff the somewhat familiar smell of slightly rotten eggs in the air (from the sulfur).
Viewing the calderas, you can see why they are quite the phenomenon. Since São Miguel is a volcanic island, there are areas where water is heated by the Earth's core.
Since the pictures don't really do it much justice, please enjoy this video clip.
You're probably asking, "Why is this post on a food blog?" Well, to answer your question, the calderas are also used to cook on. Think of the word "caldera" having the same root as the word "cauldron". Pots of meat and vegetable stews are placed either in the hot boiling water or in the surrounding ground/mud. The high temperatures of the environment make it possible for the ground to be used as natural elements and ovens. Talk about living green!
Also, exclusive to the area, is a bread known as "bolos lêvedos". The name literally translates to "leavened cakes", but the product is really known as a bread.
The bread is made with very simple ingredients including: flour, eggs, sugar, milk, butter, salt and yeast. It is cooked on a flat surface, similar to the process used when making pancakes.
The result is a bread that is somewhere in between a bread and a cake. It has many nooks and crannies similar to English muffins, with a slightly sweet flavour.
This bread is fantastic with any meal or as snack. I'm currently reviewing some recipes to see if I can make this delight at home.