Do you remember the reactions about ten years ago when Canadian architect Frank Gehry and his Croatian colleague Vlado Miluni? unveiled the office block known as Tancící dum (the Dancing House)? Every Prague citizen has a firm view on this postmodern riverfront pile near the Jiráskuv Bridge. The building seems to be loved and loathed in about equal measure.

Now it is another modern development that has fuelled the flames of architectural debate in Prague. The Czech Republic's foremost architect Jan Kaplický has come up with an unorthodox design for a new national library: a sort of multicoloured octopus that will soon be taking shape next to Letná Park.