The Hogwarts library is located on the fourth floor (PS12). Dumbledore stored the Mirror of Erised in an unused classroom on this floor as well during the fall term of the 1991-1992 school year (PS12). A painting of a landscape hangs in the fourth floor (PA8). A very roomy secret passage to Hogsmeade was located behind a big mirror on the fourth floor, but it caved in during the winter of 1992-1993 (PA10, OP17). There is a bathroom on this floor (OP28). One of Harry’s “trusted short cuts” is located about half-way down the fourth floor corridor, hidden behind a tapestry. It’s a narrow staircase which descends two floors. Half-way down that staircase is a trick step which has been known to trap the unwary including Neville frequently, and Harry on one memorable occasion (GF25). Harry used this shortcut to chase Snape after Dumbledore’s death (HBP28). Another shortcut, probably also on the fourth floor, provides a quick way up to Gryffindor Tower (HBP18).
Astronomy Tower Dungeons and other subterranean chambers Gryffindor Tower Headmaster’s Office Tower Hogwarts corridors Hogwarts fifth floor Hogwarts first floor Hogwarts fourth floor
Hogwarts ground floor Hogwarts grounds Hogwarts second floor Hogwarts seventh floor Hogwarts sixth floor Hogwarts third floor Hogwarts Towers Madam Hooch’s office