Billfastersberg

Billfastersberg is a lonely mountain covered in ancient ruins known as the Temples of Atterial, and is the home of the Muses of Poorthwart. Tyco Brahe, the Admiral and Upwhiac encounter it in Tutor Milk's head, but are clearly only visiting it through psychic means. It is clear that Tyco Brahe has been there before, but it is left unspecified as to where in Poorthwart the actual mountain is. It does not appear on Tyco's comprehensive map of Poorthwart, leading some to speculate that it is yet another feature of Level 4.