The historic centre 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 south of the equator; the city itself extends to within about of zero latitude. A monument and museum marking the general location of the equator is known locally as "la mitad del mundo" (the middle of the world), to avoid confusion, as the word "" is Spanish for equator.