Climbing to the top of a cathedral wasn't even on my radar when I arrived in León. My Spanish teacher recommended it and I'm glad she did, even if it meant cutting two hours of class to do it, or wait--was that another benefit. The climb to the top is only open 9-12 Monday thru Saturday. The views of the city are beautiful. Don't be surprised when you need to take off your shoes. I guess that's how they keep it so gleaming white.