A secret of Hogwarts, the Room of Requirement only reveals itself when someone in need walks past it three times thinking about what they need. It is thought to bear some degree of sentience, as it transforms into whatever the person using the room needs at the moment. While the room is able to produce next to everything, there are limitations, and the room is unable to provide food to those inside. It's located on the seventh floor of Hogwarts, opposite the tapestry demonstrating the attempt of Barnabas the Barmy to teach trolls ballet. The users of the room are advised to be very specific about what they are looking for, as it's been shown others are able to find the room and see what the occupants are doing if they know the room is in use. It is also in this manner the room can be used to keep certain people out, if the user specifically asks the hideout to keep certain people out.
