The Galápagos Islands (Spanish: Islas Galápagos) are an archipelago of volcanic islands in the Eastern Pacific, located around the Equator 900 km (560 mi) west of the mainland of South America. They form the Galápagos Province of the Republic of Ecuador, with a population of slightly over 33,000 (2020). The province is divided into the cantons of San Cristóbal, Santa Cruz, and Isabela, the three most populated islands in the chain. The Galápagos are famous for their large number of endemic species, which were studied by Charles Darwin in the 1830s and inspired his theory of evolution by means of natural selection. All of these islands are protected as part of Ecuador's Galápagos National Park and Marine Reserve.
Thus far, there is no firm evidence that Polynesians or the indigenous peoples of South America reached the islands before their accidental discovery by Bishop Tomás de Berlanga in 1535. If some visitors did arrive, poor access to fresh water on the islands seems to have limited settlement. The Spanish Empire similarly ignored the islands, although during the Golden Age of Piracy various pirates used the Galápagos as a base for raiding Spanish shipping along the Peruvian coast. The goats and black and brown rats introduced during this period greatly damaged the existing ecosystems of several islands. English sailors were chiefly responsible for exploring and mapping the area.