For Spain, there is a great map site :
http://www.ign.es/iberpix/visoriberpix/visorign.htmlkind of equivalent to the other one (which was catalunyan

There is now a crowd of such map portals in Europe, but so far only 3 of them include the embedding and GPX features: France, UK and ...Slovakia

For Spain unfortunately we have only the Google Maps.
To embed a google-mapped route easily you can try
http://www.wandermap.net, a great tool.
Otherwise, for more precise maps, you can try a simple JPEG of a portion of the following maps :
http://www.cimbre.com/mapas/pirineos/But I have no idea of the copyright policy of Spanish editors. Looks like many people do it on the web, much more than with the french IGN... so perhaps you can.