For as long as sculptures have decorated buildings, sculptors have tailored their creations to their sites. The ancient world is littered with examples, such as the reliefs that rise up the interior walls of the monumental stairway of the Pergamon Altar, from around 170 BCE. Depicting a battle between the gods and giants, the figures spill into our space, with knees and other body parts deliberately carved so that they appear to rest on the same stairs we climb. We are immersed in the action—all part of the ritual of approaching the altar.