Guayaquil is a coastal city with no volcanoes, but Chimborazo is the closest volcano to Guayaquil. Mount Chimborazo lies some 137 m. (222 km.) west from Guayaquil. Chimborazo is the highest volcano in Ecuador, located near Riobamba, Chimborazo. Other volcanoes are El Altar — caldera, and Tungurahua — an active volcano.
If you are willing to travel a little more, going north is the Quilotoa caldera and the Cotopaxi volcano. Both of them are great tourist destinations.