Head on over to Berlin’s Hamburger Bahnhof (a former railway station) from now till January 15, 2012, and get ready to feel like you’ve stepped into a strange and surreal dream. Artist Tomás Saraceno has created a massive installation consisting of 20 large balloons, some of which you can actually enter. Bounce on the transparent floors and then look through the spheres to see a network of cables that keep the balloons afloat. 

Inspired by soap bubbles and spider webs, Saraceno calls this installation Cloud City

"Tomás Saraceno’s installations shatter traditional concepts relating to place, time, gravity and traditional ideas as to what constitutes architecture. His works are utopian and invite the viewer to play a part in their impact on a particular space, as they reach up to the sky and down to the ground. The artist creates gardens that hang in the air and allow visitors to float in space, fulfilling a dream shared by all humankind."