The exteriors of Orlok's castle were filmed at Hunedoara Castle, also known as Corvin Castle, a Romanian castle located in Transylvania and one of the largest medieval castles extant in Europe.
According to Bill Skarsgård, his voice was the aspect of the part he worked hardest at, spending six weeks before shooting not doing "much else than just record myself". "And on set, I would keep doing these exercises. It sounds kind of like Mongolian throat-singing. It's [insane]."
The snow used in the movie is not computer-generated. Director Robert Eggers used a technique from the 1940s where frozen potato flakes are crushed and made into snow-like particles. The once-common practice of using snow candles to achieve fake snow effects has been banned on movie sets due to the fact that a toxic gas is emitted. Most people suggested using CGI, but Eggers refused and eventually decided on frozen potato flakes while watching old movies that used the technique.
Bill Skarsgård trained with an Icelandic opera coach to lower his voice an octave to make the voice of Count Orlok as deep as possible.
One historically used method for identifying the grave of a vampire, which is seen in the film, was to lead a virgin woman riding atop a virgin stallion through a grave-yard. Supposedly the horse would balk or stomp at a grave containing a vampire, and the identified grave would then be opened and the corpse dealt with. The required color of the horse varied from region to region. Typically a black horse was required, though white horses, like the one used in the film, were used in the Albanian region. The sex of the virgin also varied, with it being more common to use a virgin male child. The virgin was usually clothed in either case.
Robert Eggers: [folkloric, mythological, and fantastical period piece] The Witch (2015), The Lighthouse (2019), The Northman (2022), and this film are period pieces that are based on folklore, mythology, and fantasy, which reflect through their atmospheres, settings, and environments.
Robert Eggers: [ominous-looking animals that haunt the main characters] In this film, rats, dogs, and wolves haunt, intimidate, and attack several of the main characters and background characters during most of the film. In The Witch (2015), farm animals such as goats, chickens, and rabbits haunt and intimidate the family. In The Lighthouse (2019), seagulls constantly haunt and intimidate Thomas Howard throughout the film.
Robert Eggers: [a character named Thomas] In this film, one of the main characters' names is Thomas Hutter. In The Lighthouse (2019), another Eggers film, two of the main characters' names are Thomas Wake and Thomas Howard. In Eggers' first feature film, The Witch (2015), the main female character's name is Thomasin. The name Thomasin or Tomasin is the feminine version of the name Thomas.
Robert Eggers: [Ralph Ineson] Ineson is a cast regular for Eggers. Eggers' other films, in which Ineson starred, are The Witch (2015) and The Northman (2022), respectively.
Robert Eggers: [collaborating with a member of the acting Skårsgard Family] For this film, Eggers collaborates with Bill Skarsgård, who portrays Count Orlok. Previously, the director collaborated with Alexander Skarsgård, Bill's brother, on The Northman (2022).