structural:reformatting
Physical geography

The islands are located in the eastern Pacific Ocean, 973 km (605 mi) off the west coast of South America. The majority of islands are also more broadly part of the South Pacific. The closest land mass is that of mainland Ecuador, the country to which they belong, 926 km (500 nmi) to the east.

The islands are found at the coordinates 1°40'N–1°36'S, 89°16'–92°01'W. Straddling the equator, islands in the chain are located in both the northern and southern hemispheres, with Volcán Wolf and Volcán Ecuador on Isla Isabela being directly on the equator. Española Island, the southernmost islet of the archipelago, and Darwin Island, the northernmost one, are spread out over a distance of 220 km (137 mi). The International Hydrographic Organization (IHO) considers them wholly within the South Pacific Ocean, however. The Galápagos Archipelago consists of 7,880 km (3,040 sq mi) of land spread over 45,000 km (17,000 sq mi) of ocean. The largest of the islands, Isabela, measures 2,250 square miles (5,800 km) and makes up close to three-quarters of the total land area of the Galápagos. Volcán Wolf on Isabela is the highest point, with an elevation of 1,707 m (5,600 ft) above sea level.

The group consists of 18 main islands, 3 smaller islands, and 107 rocks and islets. The islands are located at the Galapagos Triple Junction. The archipelago is located on the Nazca Plate (a tectonic plate), which is moving east/southeast, diving under the South American Plate at a rate of about 2.5 inches (6.4 cm) per year. It is also atop the Galápagos hotspot, a place where the Earth's crust is being melted from below by a mantle plume, creating volcanoes. The first islands formed here at least 8 million and possibly up to 90 million years ago.

While the older islands have disappeared below the sea as they moved away from the mantle plume, the youngest islands, Isabela and Fernandina, are still being formed. In April 2009, lava from the volcanic island Fernandina started flowing both towards the island's shoreline and into the center caldera.

In late June 2018, Sierra Negra, one of five volcanoes on Isabela and one of the most active in the Galapagos archipelago, began erupting for the first time since 2005. Lava flows made their way to the coastline, prompting the evacuation of about fifty nearby residents and restricting tourist access.