Throughout Spanish America and the Spanish East Indies, the plaza mayor of each center of administration held three closely related institutions: the cathedral, the cabildo or administrative center, which might be incorporated in a wing of a governor's palace, and the audiencia or law court. The plaza might be large enough to serve as a military parade ground. At times of crisis or fiesta, it was the space where a large crowd might gather. Like the Italian piazza, the plaza remains a center of community life that is only equaled by the market-place.
Most colonial cities in Spanish America and the Philippines were planned around a square plaza de armas, where troops could be mustered, as the name implies, surrounded by the governor's palace and the main church. A plaza de toros is a bullring.
In modern usage, a plaza can be any gathering place on a street or between buildings, a street intersection with a statue, etc. Today's metropolitan landscapes often incorporate the "plaza" as a design element, or as an outcome of zoning regulations, building budgetary constraints, and the like. Sociologist William H. Whyte conducted an extensive study of plazas in New York City: his study humanized the way modern urban plazas are conceptualized, and helped usher in significant design changes in the making of plazas.