Iber.chebro.es/SitEbro/sitebro.aspx
Zoom in on where you want and then finca borders appear. Click on the info tab in the box and it links to the catastro site for details of the finca. You can only get details of owners of lands if you've registered your seda electronico.
This is actually why I was asking for the sede site here a few weeks ago. : )
I came across lots of very cheap, large land up that way on milannuncios.com , less than 50c a m2 in some cases. : /
Good luck.
Bruixot