well there ARE many many good bands in Spain and thanxgod from many genres!!! Mago de oz and tierra santa seem to be the ones to outstand abroad, and sure Baron Rojo DID!!!
now keep in mind these names.....
oldies (in the baron rojo wave): muro, leño, asfalto, ñu, sangtrait, bellabestia, sangre azul, medina azhara
newers (heavy_powermetal): avalanch, dark moor, ankhara, lujuria, redwhine, azrhael, saratoga, easy rider, su ta gar
prog: overlife, phakner
aor: skyline, elite
death_dark: ASGAROTH, NAHEMAH, symawrath, bleeding sun, in thousand lakes...
hardcore_industrial: Soziedad alkoholica, Ktulu, Kop
I miss many but well a big bunch of them are listed here
IMHO my alltime fave band from Spain is Heroes del Silencio but they're not metal and split in 96
so I guess you see I'm quite into it