Ensenada
Alternative Rock bar which has Rock bands playing live and sometimes also some Metal bands.
Long established venue for Metal gigs, although the shows are pretty underground and don't happen on a regular basis. Gigs are organized by the El Vertice staff, so maybe there you can find out about upcoming gigs.
Music store which has exclusive Metal stuff. Also organisators of gigs at Bar Balboa.
A place where they have all kinds of gigs from time to time, also some Metal ones.