Man, the immediate thing that jumps out is the sense of decay. It's never a pristine, new castle. You're looking at crumbling battlements, tapestries that have gone threadbare, and portraits where the eyes seem to have faded just enough to make them unsettling. The architecture itself feels oppressive—think vaulted ceilings so high they disappear into shadow, and narrow, winding staircases that lead you someplace you didn't intend to go. Windows are key, too. They're either these huge, arched things rattling in a storm, or they're mere slits, cutting the outside light into thin, grim blades that barely touch the stone floors. It all works to make you feel watched by the very walls, like the house is a character with its own, very bad, intentions.
I always get stuck on the layout. Nothing is convenient. Rooms are always distant, connected by long, draughty corridors where candles gutter. There's a deliberate inconvenience to it, forcing isolation and strange encounters. Secret passages and forgotten wings are practically mandatory, serving as physical manifestations of the family's buried secrets. The whole place is a maze, both literal and metaphorical, designed to disorient and trap the characters within its history.