Kafka's Head is another David Černý sculpture but on a massive scale. It stands 10.2 metres tall and is made up of 42 independent rotating tiers, held together by a kilometre of cable, driven by a motor and series of relay motors, and weighing in at 39 tonnes.
The whole assembly was erected in late 2014 above Národní třída metro station at the back of the Quadrio shopping mall and business centre (or here on Google maps).
Have a look at the video...(which seems not to show up in Safari. If you can't see the embedded video, trying clicking here)