Marketplace (Civ3)/Civilopedia

As cities grew and prospered, trade between the farmers, artisans, and craftsmen who lived in the vicinity contributed to the 
economic health of the city. It soon became apparent that the best way for conducting trade within the city was to have a central 
location, or marketplace, where the people offering goods and services, or seeking them, could meet and conduct business. As a city's 
marketplace grew larger and more active, the economic vitality of the city grew as well.