Ambato, Ecuador
Ambato lies in the main valley of the Central Cordillera, the highest of the Andean mountain ranges. The city itself is carved into the side of Cerro Casigana, the mountain that dominates the north end of the city. From Ambato, it is possible to see many snow-capped volcanoes including Cotopaxi, Tungurahua, Carihuairazo, and the largest mountain in Ecuador, Chimborazo. Tungurahua lies about 40 kilometers to the southeast. The threat of eruption from the volcano is constant. On May 16, 2006, Tungurahua erupted, covering the city with a thick layer of ash.
National Polytechnic School (Ecuador)
Reventador is an active stratovolcano which lies in the eastern Andes of Ecuador. Since 1541 it has erupted over 25 times with most recent eruption in 2009, but the largest historical eruption occurred in 2002. During that eruption the plume from the volcano reached a height of 17 km and pyroclastic flows went up to 7 km from the cone. On March 30, 2007, the mountain spewed ash again. The ash reached a height of about two miles (3 km, 11,000 ft).