Once upon a time...
Neuschwanstein Castle in Allgau, Bavaria, Germany | See more Amazing Snapz
The beautiful castle of Elz in Germany // Martijn van Geloof
Oberhofen Castle on Lake Thun / Switzerland (by kurt.fotosuisse).
Hunyad Castle, Romania
Peles Castle - Romania
Medieval Tower, Hungary. This is apparently near Visegrad, one of the towns on the tour round the river bend