The Galapagos Islands, an archipelago more than 500 miles off Ecuador in the Pacific Ocean, were made famous by Charles Darwin's theory of natural selection, which was formed from observations the British naturalist made to the islands during his famous voyage of the HMS Beagle in 1830s.
The 19 mostly uninhabited islands' unique geology and isolation are home to hundreds of unique flora and fauna found nowhere else in the world, including the giant Galapagos tortoise, the largest living tortoise. It's also the first animal depicted in Sunday's Google's slideshow Doodle celebrating the anniversary of the islands being declared a UNESCO World Heritage Site in 1978.
UNESCO, short for United Nations Educational, Scientific and Cultural Organization, applies the World Heritage Site designation to landmarks or areas that have cultural, historical, scientific or another form of significance, giving them legal protections under international treaties. Other UNESCO sites commemorated by Google Doodles include Ireland's dramatic and , a mystical island off the coast of Ireland made famous to millions of movie fans through the most recent Star Wars movies.
Darwin made his famous visit to the Galapagos Islands in 1835 during a round-the-world voyage. Primarily interested in geology at the time, Darwin referred to the archipelago as "that land of craters" and through his observations, explained how volcanic tuff is formed. But he also noticed that mockingbirds differed from island to island, an observation that led to his theory of evolution as detailed in his 1859 book On the Origin of Species.
In addition to the Galapagos tortoise, the slideshow features the blue-footed booby, iguanas, the fur seal and the only penguin known to live north of the equator.