One of the youngest islands, Isabela is located on the western edge of the archipelago near the Galápagos hotspot. At approximately 1 million years old, the island was formed by the merger of 6 shield volcanoes - Alcedo, Cerro Azul, Darwin, Ecuador, Sierra Negra, and Wolf. All of these volcanoes except Ecuador are still active, making it one of the most volcanically active places on earth. Two of the volcanoes, Volcan Ecuador and Volcan Wolf (the island's highest point with an elevation of 1,707 m [5,600 ft]), lie directly on the equator. The island is primarily noted for its geology, providing excellent examples of a geologic occurrence that created the Galápagos Islands including uplifts at Urvina Bay and the Bolivar Channel, tuff cones at Tagus Cove, and Pulmace on Alcedo and Sierra Negra, one of the most active volcanoes in the world.
Isabela is also interesting for its flora and fauna. The young island does not follow the vegetation zones of the other islands. The relatively new lava fields and surrounding soils have not developed the sufficient nutrients required to support the varied life zones found on other islands. Another obvious difference occurs on Volcan Wolf and Cerro Azul; these volcanoes loft above the cloud cover and are arid on top.
Isabela's rich animal, bird, and marine life is beyond compare. Isabela is home to more wild tortoises than all the other islands. Isabela's large size and notable topography created barriers for the slow-moving tortoises; apparently the creatures were unable to cross lava flows and other obstacles, causing several different sub-species of tortoise to develop. Today, tortoises roam free in the calderas of Alcedo, Wolf, Cerro Azul, Darwin, and Sierra Negra.
Introduced goats multiplied to over 100,000 but were eradicated by the Galápagos National Park Service and the Charles Darwin Foundation in 2006-2007. Since then, the vegetation has recovered greatly.
Other noted species include penguins, cormorants, marine iguanas, boobies, pelicans and Sally Lightfoot crabs abound. Galápagos land iguanas, Darwin's finches, Galápagos hawks, Galápagos doves, and very interesting lowland vegetation. The west coast of Isabela in the Bolivar Channel is the best place in Galápagos for viewing whales and dolphin.
The settlements of Puerto Villamil and Santo Tomás were founded in 1893. By 1905, the population of the island was 200. Exports at the time were sulfur mined from fumaroles and lime made from coral. Tortoises were used for meat and oil.
The third-largest human settlement of the archipelago, Puerto Villamil, is located at the south-eastern tip of the island.
Other popular attractions include El Muro de las Lágrimas (a wall built by prisoners when the island was a penal colony) and the Flamingo Lagoon (with occasional pink visitors). Both are in the south of the island.