Commensurate with other large cities in the Andean highlands of South America, Cochabamba is a city of contrasts. Its central commercial districts, Zona Norte, bounded by Plaza Colón and Plaza 14 de Septiembre, are generally equipped with modern urban amenities and are where the majority of the city's formal business and commercial industries are based. La Cancha, the largest open air market in South America, is also an active place where locals can buy a range of items. An active nightlife is centered around Calle España and along the broad, tree-lined boulevard, El Prado. In contrast, the Zona Sur, a remote area adjacent to the Wilstermann International Airport is visibly impoverished, with adobe homes and unpaved roads, which is often the first impression visitors acquire while commuting into the city.