The maps on xrei.com are drawn by us from official and open data. Each map names the sources it uses under it, and each name links to its entry on this page.
CAOP - Official Administrative Map of Portugal
The boundaries of the regions, districts, municipalities and parishes on our maps come from the Carta Administrativa Oficial de Portugal (CAOP), published by the Direção-Geral do Território (DGT). Geographic information provided by the Direção-Geral do Território, under the Creative Commons Attribution 4.0 licence (CC BY 4.0). We adapted the data: the boundaries are simplified and cut to the coastline.
https://www.dgterritorio.gov.pt/
https://creativecommons.org/licenses/by/4.0/
OpenStreetMap
The coastline, rivers and lakes on our maps come from OpenStreetMap, a world map built by volunteers. Map data © OpenStreetMap contributors, available under the Open Database License (ODbL).
https://www.openstreetmap.org/copyright
GEBCO - General Bathymetric Chart of the Oceans
The sea floor on our maps comes from the GEBCO 2026 Grid. GEBCO works under the International Hydrographic Organization (IHO) and the Intergovernmental Oceanographic Commission of UNESCO. Source: GEBCO Compilation Group (2026) GEBCO 2026 Grid.
https://www.gebco.net/
NASADEM - NASA
The land heights on our maps and height charts come from NASADEM, made by NASA. NASA does not endorse this website.
https://www.earthdata.nasa.gov/