Dumbledore is in the bathroom of the English manor, ready to go into the secret wizard building. He goes up to the decorative tree positioned in middle of the massive luxurious bathroom. He looks around to make sure no muggles are around, then takes out a pouch from his pocket and presses it against the tree. The tree instantaneously turns into a small building that he enters. Once he enters, the building turns back into a tree. Now that is some real magic.