Witchfate Tor is a piece of Warhammer Fantasy scenery released in November, 2010.
It does not represent any particular monument as far as we know, but is a generalized tower used by a Wizard for isolation from the outside world in which they could conduct their experiments.
Notably inside on the bottom floor are a sewer grate suggesting a need for drainage and some form of plumbing (as well as a small hold on the base side to string a wire in to cause light to come up through said grate), a circle with emblems for each of the Winds of Magic, and broken cracks in the floor which reveal skulls underneath (not exactly a rarity in Warhammer architecture however, as rocks form into skull shapes naturally for whatever reasons). On the removable second floor, connected by stone stairs, is a wooden floor with gaps between the floorboards and shackles one one side of the room. Up another flight of stairs is another, similar floor. The top floor is reachable by two wooden trapdoors, leading to an open area with a crenellated parapet around it. The floor tile depicts the iron cross of the Empire along with iconography of Sigmar including the Heldenhammer and Twin-Tailed Comet. The outside of the parapet is decorated with skulls, shields with the Twin-Tailed Comet, and hourglass icons of Morr.
Wall sections can be used at any point in the tower, and each level requires four. One has an emblem of Tzeentch visible from behind a bricked-up wall, either showing the master of the tower is a secret cultist, the tower was taken by another master who did not share the same allegiance, or Tzeentch can manipulate stonework with his corruption from a distance (not like he isn't a dick enough to put it there just for a Wizard who may have saved the Empire to be shot unceremoniously by visiting Witch Hunters instead). One panel has a depiction of Morr, another two have stacks of bones on the outside like a catacomb. Inside there are cubbies containing books and candles, or skulls stacked. There are a few with windows, some more elaborate and some simple. Furthermore there are several gates which lead to an external place for a character to stand, two of stone depicting the Twin-Tailed Comet and one of wood.
Around the base is steps leading up to the entrance gate, and four pillars with skulls.
It originally retailed for $99, although after it fell out of production surviving copies shot up in price (partially because you can use multiple sets to add two more floors each, making a fuckhuge tower).
We don't know how it managed to survive the end of the fucking world, only that it did. It was brought back to be sold and given its own rules, but later on qas squatted again.
Witchfate Tor in AoS, where it also apparently retained the Storm of Magic upgrades like a face, breathing fire, and flying based on the reused art.