It's potentially the Norfolk & Norwich Festival's biggest ever event: an open-air gallery that covers a large swathe of Norwich city centre.

But Streetwalker Gallery is not entirely what it seems. The artworks here are formed from the existing landscape: from bike locks, phone boxes and long-forgotten signs hanging from buildings.

There was a strong risk that this could be post-modernity squared: a pseuds' adventure that disappears up its own fundament. But its main physical characteristic is actually a tongue firmly implanted in its cheek. Bird droppings become an abstract masterpiece, some prominent railings become a 'DIY Titanic' scene.

This is playful and fun, particularly the guided tours where the 'gallery workers' are performance artists in their own right and encourage the audience to join in: somehow I ended up standing in a bin pretending to be an astronaut.

The 'exhibits' are available until May 25, but if you can take one of the twice-daily tours running until Sunday and see Norwich in a whole new light.