It is a Zebra Ducky Plane or possibly A Tiger Ducky Plane (at least one of them is a character from a German children’s book series and the plane had ENTE (i.e. duck) written on its tail.
Castle Schönburg (literally Beautiful Castle) is situated on the Schönberg (literally Beautiful Mountain) above the town of Oberwesel in the UNESCO world heritage site “Rhine Valley”. And nowadays it’s a rather exclusive hotel.