Popocatepetl and Iztaccíhuatl

This 2003 photo from the International Space Station shows a pair of volcanoes in Mexico. As part of the “Ring of Fire” stretching around the Pacific, Mexico hosts several of the world's most continually active volcanoes, including the massive Popocatepetl (Aztec for "smoking mountain") at left. The neighboring volcano is Iztaccíhuatl (the "Woman in White"). The faint plume emanating from Popocatepetl's summit crater shows the ever-present hazard the volcano represents to the 25 million people living in the region, including the nearby city of Amecameca, as well as the metropolitan centers of Mexico City to the northwest and Puebla to the east.
Credit: NASA