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.
Monserrate Palace, Sintra, Portugal is a beautiful century stately home. This extravagantly decorated palace blends Portuguese, Arabian and Indian architectural styles and is one of the most beautiful buildings in Sintra.