Cloud Cities – installation by Tomás Saraceno In Berlin’s Hamburger Bahnhof. Saraceno has installed over 20 huge spheres suspended at different heights in a network of black mesh. Within each orb is a different organic material like water or plants or air. This work is inspired by soap bubbles and spider webs (and the interaction and juxtaposition). We think of those two items as fragile and delicate, but they are actually extremely flexible and (for the material) super strong.