I have two little daughters myself and I can relate to parents when they say they are building a wall for their kids. I often hear the parent say that they have an 18 month old. Of course we all know that is too young to be climbing on a vertcial wall but they can on an angled wall!
A simple 5 piece puzzle perfect as an eductaional toy and when the little tikes grow out of it, use it as holds on your wall!
This is a great gift for the little ones.