et in arkham ego

'' he was in the changeless legend haunted city of arkham, with its clustering gambrel roofs that sway and sag over attics where witches hid from the king's men in the dark olden days of the province ...


'' nor was any spot in that city more steeped in macabre memory than the gable room which harboured him--for it was this house and this room which likewise had harboured old keziah mason, ... she had told judge hathorne of lines and curves that could be made to point out directions leading through walls of space to other spaces beyond, ... then she had drawn those devices on the walls of her cell and vanished ...


'' old keziah he reflected might have had excellent reasons for living in a room with peculiar angles for was it not through certain angles that she claimed to have gone outside the boundaries of the world of space as we know it? ... he knew his room was in the old witch house ... that, indeed was why he had taken it ...


'' gilman's room was of good size but queerly irregular shape the north was standing perceptibly inward from the outer to the inner end, while the low ceiling slanted gently downward in the same direction ... there was no access--to the space which must of existed between the slanting wall and straight outer wall on the houses north side, ...


'' the curious angles of gilmans room had been having a strange, almost hypnotic effect on him ... he had found himself staring more and more intently at the corner where the down-slanting cieling met the inward-slanting wall ... his absorption in the irregular walls and cieling of this room increased, for he began to read into the odd angles a mathematical signifigance. ''

h.p.lovecraft, dreams in the witch house.

i: a book by john modrow containing some cautionary advice on staring too intently at the cracks in the cieling, peeling paint, and strange angles of your room.
ii:witch house k in sapporo by sekkei-sha
ii: witch house in argentina.