La Paz was built in a canyon created by the Choqueyapu River (now mostly built over), which runs northwest to southeast. The city's main thoroughfare, which roughly follows the river, changes names over its length, but the central tree-lined section running through the downtown core is called the Prado.
La Paz' geography,(in particular, altitude) reflects society: the lower you go, the more affluent. While many middle-class paceños live in high-rise condos near the center, the really rich houses are located in the lower neighborhoods southwest of the Prado. The reason for this division is that the lower you go in the city the milder the weather is. And looking up from the center, the surrounding hills are plastered with makeshift brick houses of those struggling in the hope of one day reaching the bottom.
The satellite city of El Alto, in which the airport is located, is spread over a broad area to the west of the canyon, on the altiplano.