• MacOS: brew install gdal
• Linux: sudo apt install libgdal-dev

go run .

Downloaded data from https://environment.data.gov.uk/DefraDataDownload/?Mode=survey:

• Zoom to preferred area (you should see the tiles appear)
• Draw a square around it
• Click "Get Available Tiles"
• Choose preferred model and resolution and download tiles
• Currently testing with DTM

GeoTIFF format. Spec: http://geotiff.maptools.org/spec/contents.html