Geography

Additional Reference Information

REGION TYPES

The type object explains the geographic entity represented such as city or neighborhood. Refer to the list of region types for detailed descriptions.

LOCALIZATION

The language object only uses hyphenated pairs of two-digit language and country codes - see parameter entry for details. Review our supported languages before integrating any codes. Only the name and name_full fields in the responses are provided in the requested language. All other geography definitions in the response will be in English.

POLYGONS

The bounding_polygon object provides the list of coordinates that encompass the shape of the region. Regions can cover areas represented by either a single polygon or multiple polygons. Region types that are represented by a single coordinate (e.g. point of interest, train station, airport, etc.) do not have a bounding polygon. The bounding_polygon object follows the GeoJSON standard with the longitude value listed first followed by latitude when providing lists of coordinates.

HIERARCHY BETWEEN REGIONS

The relationship between regions is provided using the ancestors and descendants objects. Due to geographical and political variations throughout the world, region types do not have a strict hierarchy. Logically, however, a city is typically associated with a multi-city, province/state or country. To derive the hierarchy of a specific region, use the ancestors values.

• ancestors represent the levels of hierarchy above a given region. For example, the direct ancestor of the multi-city of Athens, Greece is the region of Attica and further up the hierarchy its ancestors include Greece and Europe. A region may have more than one parent. Since the multi-city of Geneva is on the border of Switzerland and France, it will have ancestors in both countries.
• descendants represent the levels of hierarchy below a given region. In our example, the city of Piraeus, Greece is a descendant of the multi-city of Athens, Greece. The descendants map within a region object only contains the direct children (one level down) of that region.

RELATIONSHIP BETWEEN REGIONS AND AIRPORTS

Airports in our geography system have an associated_region which represents the city or multi-city most commonly associated with the airport. For example, the associated region for LHR is the multi-city of London, England.

IATA location codes: Airports API contains 3 character IATA airport and corresponding metropolitan codes. These can be searched for by iata_airport_code.

PROPERTY MAPPINGS FOR REGIONS

Property mappings are provided for the Region and Regions API. Region types with property mappings are: high_level_region, state_province, multi_city_vicinity, city, neighborhood, point_of_interest, and select countries. Property mappings are available in two include parameter options:

• property_ids: This option provides only the properties within the region's polygon. The polygon is the bounding shape that represents the region’s area.
• property_ids_expanded: If the region’s polygon does not contain at least 100 properties, this option provides the properties within the polygon in addition to properties within a 30km radius of the region. This expanded set of properties should ensure that enough properties are presented in property search results for a destination. For region types represented by a single coordinate rather than a polygon (e.g. point of interest), only this expanded option will provide associated property mappings.

Polygons are optimized to use search and transaction data and will expand smaller regions outside of the polygon where most relevant.

PROPERTY MAPPINGS FOR AIRPORTS

Property mappings in relation to the airport are provided in both the Airports API and the Airport API. These mappings are available in two include parameter options:

• property_ids: This option provides only the properties within a 20km radius of the airport.
• associated_region_property_ids: This option provides the properties within the polygon of the associated region. The associated region is the city or multi-city most commonly associated with the airport. The polygon is the bounding shape that represents the associated region’s area.

DATABASE RECOMMENDATIONS

See the geography database recommendations for guidelines on setting up your content database.