The Instituto Geográfico Nacional (IGN), or National Geographic Institute is a Spanish government agency, dependent on the Spanish Ministry of Public Works. It is the national mapping agency for Spain, together with the Centro Nacional de Información Geográfica (CNIG). Since 2015, most of its products (including MTN50 and MTN25 topographic maps, and PNOA aerial photographies) are freely available online, and licensed under a CC-BY-4.0-like license, as FOM/2807/2015 decree requires its products must be released under a free license. From Wikipedia
