The Settlements and Landscapes hierarchy contains terms for the largest features of the built environment, whether relatively concentrated (e.g., "retirement communities") or extensive (e.g., "capital cities"). Settlements are defined as all places or areas, larger than a single dwelling or complex, occupied or modified by human populations and with certain societal functions. Also included in this hierarchy are terms for natural landscape and cultural landscape. By placing natural landscapes in this hierarchy, the AAT has chosen not to emphasize a distinction between the natural environment and the built environment, for which it may be difficult to define a distinction. Relation to other hierarchies: Administrative bodies (e.g., "nations," "provinces") are located in the Organizations hierarchy. Adjectival attributes of some settlements (e.g., "radial plan") are found in the Associated Concepts hierarchy. Terms referring to individual plants and trees are found in the Living Organisms hierarchy (e.g., "Pinus (genus)"), while terms for general areas of vegetation (e.g., "jungles," "shrubs") are found here. Terms for infrastructural systems, networks of buildings, other structures, and equipment that constitute physically ordered entities within settlements and landscapes (e.g., "bus transit systems") are located in the Object Groupings and Systems hierarchy.
