The Murinsel is an artificial floating island in the middle of the Mur river, designed by New York artist Vito Acconci and built for Graz's 2003 year as European Capital of Culture. A shell-shaped steel and glass structure about 50 metres long, it connects the two banks via twin footbridges and contains a café, a small amphitheatre, and a children's playground.
The design is deliberately provocative against the backdrop of Baroque and Gothic architecture. Whether you find it charming or alien probably says something about your architecture politics, but the views from inside — looking upstream toward the old town's waterfront — are genuinely good. The café is a pleasant place to sit if the weather cooperates.