Why go
Geology gives meaning to contrasts that appear quickly on a visit: broad volcanic Isabela, the younger terrain of Fernandina and dry, rocky coasts elsewhere. Understanding how islands form and move helps you see the archipelago as a changing landscape rather than a set of interchangeable wildlife stops.
The full story
The Galápagos sit on the Nazca Plate above a volcanic hotspot, where heat from below helps generate magma and build islands. As the plate moves east and southeast, volcanic land moves away from the area where it formed. Older islands can erode and eventually disappear beneath the ocean, while younger western islands such as Isabela and Fernandina continue to show the work of volcanism. Isabela dominates the archipelago’s land area, but its size does not make its whole surface a single visitor destination. Sea passages and individual access points still shape a trip. The islands also straddle the Equator, so their geography reaches into both hemispheres. Their position on the map is only part of the explanation for what you see: elevation, ocean influences and the age of the land help create the contrasts between bare volcanic rock, dry vegetation and greener uplands.