From Wikipedia: Quito is the capital city of Ecuador, and at an elevation of 9,350 feet (2,850 m) above sea level, it is the highest official capital city in the world. It is located in the Guayllabamba river basin, on the eastern slopes of Pichincha, an active stratovolcano in the Andes mountains. With a population of 2,671,191 according to the last census (2014). The historic center of Quito has one of the largest, least-altered and best-preserved historic centers in the Americas. Quito, along with Kraków, were the first World Cultural Heritage Sites declared by UNESCO in 1978. The central square of Quito is located about 25 kilometres (16 mi) south of the equator; the city itself extends to within about 1 kilometre (0.62 mi) 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 ecuador is Spanish for equator.
Please see also Cool2visit.com for more info and this article about Quito: Colonial beauty and starting point for adventures. Plus this webpage here from Wikitravel for travel related information about Quito, Ecuador.
Here we attach a few images from a visit to Quito some years back.