The Murinsel (German, literally Mur island) in Graz, Austria, is actually not an island at all, but an artificial floating platform in the middle of the Mur river. This landmark of Graz was constructed by New York artist and designer Vito Acconci on the occasion of Graz becoming the 2003 European Capital of Culture.

The building in the form of a giant sea shell measures 50 m in length and 20 m in width. Two foot-bridges connect it with both banks of the Mur. The center of the platform forms an amphitheatre. Below a twisted round dome there is a café and a play-ground. The Murinsel is built for a maximum number of 350 visitors.