Not only Reference Systems based on Geographic Identifiers is based in coordinates, but also their locations are defined by one or more geographic features.

• INE Codes: This link has the list of towns and its province codes, updated 1st of January of 2006. 

• Local Entities Registry: Link to Local Entities Registry of the Ministerio de Administraciones Públicas.

• Postel Codes: Links to the postel codes of all populations of Spain.

• Cadastral Identifiers: Link to the web page of the Virtual Office of Cadastre to make accessing to the public cadastral data, using a cadastral reference or a location.

• Tiles of MTN25: File with the tiles of the National Topographic Map 1:25.000 in DGN format. The reference System is UTM zone extended 30.