Headmistress' Office

The entrance to the Headmistress' office at Hogwarts is behind a statue of a gargole on the seventh floor. When given the proper password, the gargoyle will leap aside, and the wall behind it will split in two to reveal a spiral stone staircase that moves like an escalator. The gargoyle, however, sometimes has a mind of it's own. The office can be sealed so that no one can enter, save the rightful Headmistress[Meaning, if the Headmistress were wrongly taken from her job, and the gargoyle got mad, he'd lock the stairs so no one could enter]. Also, the office can be sealed s that someone already inside cannot leave without the Head's permission.