In general, Latin American cities are dominated by several components: a viable Central Businnes District (CBD), a Commercial Spine and an associated Elite Residential Sector, and a series of concentric zones in which residential quality decreases outward from the center of the city.
From the outset, the colonial city was laid out on a grid-iron pattern as prescribed by the Spanish monarchy and later embodied in the Laws of the Indies. Urban life centered on the CBD or the main plaza, which for Mexico City is called Zocalo Square. All governmental offices, the National Palace, and the great majority of commercial activities were located within a short distance of the plaza.
Outside of the area of the CBD, the dominant element of Latin American city structure is a Commercial Spine (Paseo de la Reforma) surrounded by an Elite Residential Sector, which is an extension of the CBD and is lined with the city's most important ammenities.
Poorer areas have developed as a series of concentric zones in the east and north. As one moves outwards, the settlements become poorer and more recently established.