Prefects' bathroom

The Prefect's Bathroom is a special bathroom restricted to use by school prefects, and the house Quidditch captains at Hogwarts. The bathroom has a large, swimming-pool like tub, with faucets surrounding it. The faucets all run different coloured water, bubbles, foam, etc. Looking at the tub, one would imagine it would take quite some time to fill, but actually fills remarkably fast, considering it's size.

Trivia

 * The password for the Prefect's Bathroom was Pine Fresh, for at least part of the 1994 school year.