Set the center for the region using Lat/Long
guildford = GeoPosition[{51.2356944, -0.5748554}];
Retrieve the elevation data for a 2 mile region around the center
data = GeoElevationData[GeoDisk[guildford, Quantity[2, "Miles"]], GeoZoomLevel -> 8]
Draw a surface plot of the raw elevation data
ListPlot3D[data, MeshFunctions -> {#3 &}, Mesh -> 40, ColorFunction -> "DarkBands"]
Create a smoothed surface plot from the elevation data with more subdued colours
ListPlot3D[data, MeshFunctions -> {#3 &}, Mesh -> 40, InterpolationOrder -> 2,ColorFunction -> "AlpineColors"]
Save a simplified version of the plot to an STL file ready for final Z scaling and printing
gr = ListPlot3D[data, PlotRange -> All, Mesh -> None, PlotStyle -> Red, Axes -> False, Filling -> Axis, InterpolationOrder -> 2];
Export["/tmp/guildford_relief_txt.stl", gr, {“STL”, “BinaryFormat” -> False}]