MapQuest - OpenStreetMap Wiki

Just replace the "http://a.tile.openstreetmap.org" bit with "http://otile1.mqcdn.com/tiles/1.0.0/osm". Note: MapQuest has 4 subdomains set up, otile1 to otile4, all pointing to the same CDN. Just like with OSM's a.tile to c.tile subdomains, these subdomai

wiki.openstreetmap.org