not obvious from the "mount" very heavy and are his only point of "weak" there are beautiful very very strong my son uses it as a game park in the living room he loves he sees us he plays in it every day at the beginning or it is held upright he fell and banged her head on the bottom a little too hard, but he quickly realized how not to fall! es stable bed pushes against the walls of all its weight the bed never move a muscle I am 100% satisfied !!!