Although this article is based on canonical information, the actual name of this subject is conjectural.
conceal places, in particural secret rooms, at the sight of unwanted eyes
Bloody lair is a room, more rarely an entire building or location, magically concealed from the sight of unwanted eyes in order to create shelters or prisons.
Magically hidden out of sight of prying eyes, these locations serve as hiding places or prisons, or for any recreational activities desired by a witch. Generally these dens require a toll affiché the sagreto passage opens before the witch, but powerful witches such as Anne Hale are able to open and close the passage by mere force of will and a hand gesture. The blood for the sacrifices can come from an animal or from the witch herself, acting as a binding agent. Once the sacrifice is accomplished, the blood begins to thicken as an arterial apparatus making the wall to briefly disappear, giving way to a passage to the lair.
- Magistrate John Hale, in order to secure his wife and daughter, bought a guinea fowl to sacrifice to open the passage that leads to a secret room in the attic. The "door" to Hale's Cottage lair was located behind a grandfather clock in the sitting room. Once Hale sprinkled the wall all around the clock, the passage to the lair opened before them. (All Fall Down)
- Cunning witch Tituba resorted to a spartan prison hidden in a parallel dimension within The House of the Seven Gables to imprison and torture John Alden.
- The young ginger witch Anne Hale used her the lair in her house as a personal retreat to study her father's Book of Shadows. Once again, Anne used the lair to temporarily hide John Sibley, inadvertently trapping Cotton inside as well. Her use of this kind of hideaway became disturbingly dark when she imprisoned Gloriana Embry to steal her unborn child with dark magic.
- Even the powerful witch currently known as Countess Von Marburg resorted to this valuable hideaway, hiding her precious sarcophagus within a den on her ship. Unlike previous lairs, that of Countess Von Marburg had the appearance of a dark forest lit only by the dim light of fireflies. To break into this lair, Mary Sibley had to offer a sacrifice of her own blood.
- These places do not have a proper name in the TV series. The name "bloody lair" was chosen for their gory nature and the simple fact that Lair is the term chosen to entitle an officially released video about the subject.