Pena de Bernal 

a little more beta, for those who find themselves wandering the central mexico rock scene. once you get to bernal, attempt the maze of uphill side streets until you find yourself at the base of the rock. a few pesos will pay the parking fees.

the via ferrata descent probably feels like 4th class on the way up, but on the way down it might get your attention if you're not on top of things. its not a via ferrata with cables, protection, etc. mostly a seriously fun down-monkeying with fattie rungs through most (but not all) of the steep sections. a 60m rope will protect the entire climbing section if you want a belayed-downclimb, or you can rappel from chains at the slabby (crux?) beginning of the descent. there is an intermediate station if rap straight down, so im assuming you could rap with one rope, but i havent tried.

i found the climbing similar to classic moderate red rock (nv) stuff, plenty of things to hold onto on the gentle climbs i played on, and the rock is solid.

there is plenty of beta (in spanish) on xpmexico.com.
click on (respectively) roca: guias, querataro, pena de bernal

There's also great bouldering around the base of this. The "via ferreta" is more like low fifth class soloing with a rung every 30 feet or so. Super fun!