Quito is the capital of Ecuador and at an elevation of 2,850 m above sea level, it is the second highest official capital city in the world, and the closest to the equator. It is located in the Guayllabamba river basin, on the eastern slopes of Pichincha, an active stratovolcano in the Andes Mountains.
In 2008, the city was designated as the headquarters of the Union of South American Nations.
The historic center of Quito is one of the largest, least-altered and best-preserved in the Americas. Quito and Kraków, Poland, were the first World Cultural Heritage Sites declared by UNESCO, in 1978. The central square of Quito is located about 25 km south of the equator; the city itself extends to within about 1 km of zero latitude. A monument and museum marking the general location of the equator is known locally as la mitad del mundo, to avoid confusion, as the word Ecuador is Spanish for equator.