Now I understand “will fail on non rectangular area” ;-)

I am fiddling around seacharts (OpenSeaMap): OSeaM-tiles are non existing in case there is nothing to show…. Could you extend your script, checking for missing y-directories (and missing x-files in missing y-directories)?

Thanks a lot, Dirk http://maps.grade.de/

P.S. https://code.google.com/p/gmapcatcher is a great tool, fetching tiles along a path. Perfect small footprint downloader in conjunction with your script :-)

Thanks a lot, just what I needed :-)