It seems as if a UFO has landed in the middle of Graz: an organic form, evoking a half shell or a snail's shell, is floating on the Mur river as an artificial island, connected by piers to both river banks. The steel construction was designed by the architect-artist Vito Acconci, based on a concept by Robert Punkenhofer, a native of Graz, and realized within the scope of "Graz 2003: Cultural Capital of Europe." Acconci Island, consisting of various interlocking surfaces with flowing transitions, houses an amphitheatre, a caf™, and a playground. Large parts of its outer stainless-steel skin reflect the city; acrylic fiber, glass, steel grids, and peepholes provide a view onto the water and the banks, while the transparent materials make the building look weightless. The result is a breathtaking, technically sophisticated avant-garde piece of architecture that refuses categorization. This publication documents the different stages of design, and places sketches and computer simulations next to remarkable photographs of models as well as shots of the finished island. An interview with Vito Acconci and a presentation of the diverse work of the Acconci Studio round off the book.