The Galápagos Archipelago, located approximately 600 miles (1,000 km) west of mainland Ecuador in the Pacific Ocean, is a globally significant natural wonder. This chain of volcanic islands is known for its extraordinary biodiversity, with many endemic species found nowhere else. The islands’ unique geological activity and isolation have created an evolutionary laboratory, making them important for scientific study and conservation.
The Official Island Count
The precise count of landmasses in the Galápagos Archipelago varies based on classification criteria. The archipelago generally includes 13 to 19 major islands, each with a land area of at least one square kilometer. Additionally, there are six smaller islands and numerous islets and rocks. Including all landforms that permanently rise above sea level, the total count is approximately 127 islands, islets, and rocks.
Of the main islands, only four are permanently inhabited by humans: Santa Cruz, San Cristóbal, Isabela, and Floreana. Baltra, though uninhabited, hosts the main airport for tourist arrivals.
Understanding Island Classifications
The distinctions between an “island,” “islet,” and “rock” in the Galápagos are based on size and ability to sustain life. A “main island” refers to a landmass exceeding one square kilometer in area, capable of supporting a diverse ecosystem and human settlements. Islets are smaller landforms, often a few hectares, which may host limited vegetation and specific wildlife. Rocks are the smallest features, often barren, providing perching or resting spots for seabirds and marine life.
The archipelago’s dynamic volcanic nature means the number of visible landmasses changes over geological time. New islands form in the western chain due to ongoing volcanic activity, while older, eastern islands experience erosion. This continuous geological process shapes unique landscapes, from rugged lava fields to pristine beaches, influencing species distribution and evolution.
Major Islands of the Galapagos
Several major islands stand out due to their size, unique features, or significant wildlife. Isabela Island, the largest in the archipelago, spans 1,771 square miles (4,586 km²) and is notable for its seahorse shape, formed by the merger of six shield volcanoes. It supports diverse species, including Galápagos penguins and flightless cormorants. Santa Cruz Island, the second largest, hosts the archipelago’s largest human population in Puerto Ayora and is home to the Charles Darwin Research Station, a center for conservation.
San Cristóbal Island, the easternmost major island, was the first island visited by Charles Darwin in 1835 and is known for its frigate birds and sea lions. Española Island, the oldest and southernmost, is a haven for unique endemic species like its lava lizard, mockingbird, and is a nesting site for the waved albatross. Fernandina Island is the youngest and most volcanically active, supporting marine iguanas and Galápagos penguins. These islands collectively showcase the diverse habitats and evolution of the Galápagos.