How to download free maps to your Garmin Edge 705/800/810/1000 & Touring
garmin.openstreetmap.nl has been broken and unable to download maps for about a month, I finally tried out openmapchest, it great wish I was using it all these years : r/openstreetmap
Map sources - Commercial and alternative GPS outdoor maps for Garmin device | TerraHunt
How to: Install Free Maps on your Garmin Edge | DC Rainmaker