From Vienna take the S5 or A1/S33 to Krems, then the B3 to Spitz, at Spitz turn right, direction Ottenschlag (B217), before Ottenschlag turn left, direction Kirchschlag and then left again, direction Roggenreith
From Melk/Linz A1 over the Donaubruecke (bridge over Danube) to Emmersdorf, then take the B3 direction Marbach to Weitenegg, turn right, direction Poeggstall (B216), after Poeggstall in Wuerndorf turn right, direction Ottenschlag (B36) and then turn right at the signpost to Roggenreith