Furnas Volcano, Azores (Portugal) / Vulcão das Furnas, Açores (Portugal)

Furnas volcano lies at the eastern end of Sao Miguel Island, immediately west of the older Nordeste shield volcano and its Povoaçao caldera.

The genesis of the Azores is found upon 1766 volcanoes, nine of which are still active. Underground, almost three hundred volcanic cavities, including caves, ravines and cracks, have been surveyed. The landscape is filled with dry calderas, craters lakes, fumaroles and thermal water springs.

Furnas contains at least two calderas, a younger one that is 6-km wide and a larger older one that is less topographically distinct. Volcanic activity at Furnas dates back about 100,000 years. Two historical eruptions have occurred at Furnas, one sometime between 1439 and 1443 and the other in 1630. The latter was one of the largest Holocene explosive eruptions in the Azores and caused significant damage and fatalities.