20th-century adaptation of the historical marketplace, with accommodation made for automobiles. A shopping centre is a collection of independent retail stores, services, and a parking area conceived, constructed, and maintained by a management firm as a unit. Shopping centres may also contain restaurants, banks, theatres, professional offices, service stations, and other establishments.

Aspects considered by planners when a shopping centre is to be built include feasibility of the site in terms of the community's ability to support a centre; adequate vehicular access; and size, access, and topography of the site, as well as availability of utilities, zoning laws, and land use in the immediate area. Economic conditions of the area, the sociology of the region, and local commercial competition and attitudes determine the size of centre that can be supported and the kind of stores acceptable to a given locale.

Shopping centres are generally of neighbourhood, community, or regional scope. The smallest type, the neighbourhood centre, usually has a supermarket as a focus, with daily convenience shops such as a drugstore, shoe repair, laundry, and dry cleaner accompanying it. Such a centre can usually serve 2,500 to 40,000 people within a six-minute drive.

The community shopping centre contains all of the above-mentioned services in addition to a medium-sized department store or variety store, which acts, with the supermarket, as a focus. Wearing apparel, appliance sales, and repair stores are also found here. This centre will normally serve 40,000 to 150,000 people.

Car-parking facilities are a major consideration in shopping-centre design. The size and scope of the centre, the type of tenant, and the economics of the area partially determine parking needs, but it has been found that a ratio of 5.5 parking spaces per 1,000 square feet of leasable space is usually adequate. Access to the lots must be broad and easy enough to avoid traffic jams. On hilly sites the use of parking and service decks apart from the main consumer level is often advantageous.

Pedestrian and vehicular circulation within the centre are prime design considerations and should be kept physically separate as much as possible. Exceptions to this rule are the satellite placement of auto-accessory stores, movie theatres, and drive-in banks.

The first unified shopping mall, Country Club Plaza, founded by the J.C. Nichols Company, opened near Kansas City, Mo., in 1922. The first enclosed mall opened near Minneapolis, Minn., in 1956. In the 1980s there developed “megamalls,” such as the West Edmonton Mall in Alberta, Can. (opened in 1981), which contained not only more than 800 stores vending everything from footwear to automobiles but also restaurants, a hotel, an amusement park, a miniature-golf course, a church, a “water park” for sunbathing and surfing, a zoo, a 438-foot-long lake, and, scattered about, more than 500 kinds of trees.