Elevation data for any country. The main data source is Shuttle Radar Topography Mission (SRTM) , specifically the hole-filled CGIAR-SRTM (90 m resolution) from https://srtm.csi.cgiar.org/. These data are only available for latitudes between -60 and 60.
The 1 km (30 arc seconds) data were aggregated from SRTM 90 m resolution data and supplemented with the GTOP30 data for high latitudes (>60 degrees).