For 2 reasons, first the staff has been trained by Johanna Wechselsberger,
Second, it is the only place in Vienna where you can drink an espresso at the bar for 1€
(just like in Italy).
So on that very day, i start my "Stella business" walk by an espresso in O.D.C.
I go out of the building, look at the list of addresses i wrote on a Post-it and read "Freyung 1".