The Art of the Woodpile

Recently been cutting and splitting and having a general tidy-up: dry-stone walling with wood. It's extremely therapeutic and could almost be passed off as art.
To stack with bark uppermost to aid the drying is supposed to be desirable(the theory being that the bark holds moisture in), and I can see that this might be the case, but a flat vertical face was more important to me.
Species? Oak, hazel, birch, hawthorn and ash (and some rubbishy roundwood with little calorific value but good for initial heat)