Church of Our Saviour on the Spilled Blood, St Petersburg, Russia. As a ghost, I am looking for a castle to haunt. What about this one? I know it isn't technically a 'castle' but look at its magnificent size! I think it would still be splendid to haunt.
(would be costly architecture, but there are some elements here I like) "Stairway to heaven: The neoclassic Romanian Atheneum, constructed in 1888 by French architect Albert Galleron, is home to the George Enescu Philharmonic Orchestra.