Maria from Bucharest, Romania writes that this is
Peles Castle. It is a Neo-Renaissance castle in the Carpathian Mountains, near Sinaia, Romania on an existing medieval route linking Transylvania and Wallachia, built between 1873 and 1914. Of the 168 rooms, only 35 are accessible to the public. This is one reason I love my new postcrossing hobby -- all the new world information I gain. This castle is beautiful! I've added Romania to the top of my list of places to visit.
Thanks for the great card baypkee (RO-18924)