Isabela is the largest of the islands. At 4,588 Sq km (1,771Sq Mi), it comprises 58% of the archipelago’s land area. Most of the islands have been formed from a single shield volcano, though some (like the Plazas) have been formed from uplifted sea floor. Isabela is made up of five large overlapping volcanoes. The hike from the lagoon at Punta Moreno takes one a short distance inland on the west side of Volcán Sierra Negra.

After about a half mile from shore over rough and fissured lava, one arrives at the first of several brackish lagoons where there is a good chance of seeing a flamingo or two. The lagoons are connected to the sea by subterranean lava tubes and contain a variety of organisms, including the shrimp favored by the flamingoes. Some of our group even spotted sharks in one of the lagoons.