High resolution map of the world with "ReliefMap", country borders and main cities

Question

I would like to generate a plot of a map of the world:

• for A0 (1189mm × 841mm) one needs 3370 × 2384 points for 72ppi
• it should range from south - north: {-90, +90}; east - west {-185, +185}
• ReliefMap
• thick black country borders
• main cities (capitals and big cities) with dots and names
• names of countries

Here is a first attempt overlaying a "StreetMap" and a "ReliefMap". But in the final version, I don't want the streets. Just the cities and country borders with their names.

ClearAll["Global`*"]  
{{n, s}, {w, e}} = {{-90, 90}, {-185, 185}};   
grm = GeoGraphics[{GeoStyling["ReliefMap"], 
        Polygon[GeoPosition[{{n, w}, {n, e}, {s, e}, {s, w}}]]}, 
          GeoRangePadding -> None];  
gc = GeoGraphics[{GeoPosition[{{n, w}, {n, e}, {s, e}, {s, w}}]}, 
       GeoRangePadding -> None,
          GeoZoomLevel -> 3];  
Show[gc, {Opacity[0.3], grm}];  

The last line results in an error. But I don't know where to put the Opacity information. And then I'm not sure how to Export with ImageSize and ImageResolution. And what would be better: pdf or png?

Answer 1

Here is a partial answer, where I generate a "ReliefMap" with country borders:

GeoGraphics[Flatten[{GeoStyling["ReliefMap", ColorFunctionScaling -> False, 
                                GeoZoomLevel -> 3], EdgeForm[Black], 
                     Table[EntityValue[cont, "PolygonCountryBoundaries"], 
                           {cont, EntityList[EntityClass["GeographicRegion",
                                                         "Continents"]]}]}], 
            GeoBackground -> GeoStyling[{"Coastlines", "Border" -> Directive[Black, Thick],
                                         "Ocean" -> ColorData["Legacy", "AliceBlue"]}],
            GeoRange -> "World"]

I have omitted putting in country names and capital locations, since the result just looked messy with them. (You can evaluate CountryData[#, "CapitalLocation"] & /@ CountryData[] yourself if you want the locations, and CommonName[CountryData[]] if you want the names.) If you want it large, you can adjust the ImageSize setting of GeoGraphics[].