The third largest – and youngest – of the Galápagos Islands, volcanically active Fernandina has a unique environment which makes it a haven for thousands of slowly-moving marine iguanas, Galápagos penguins, flightless cormorants and sea lions. This is also the island where you’re most likely to see a volcanic eruption! There is a good 15km hike to Volcan Sierra Negra which departs from Puerto Villamil.