Seeing bubble… For the fifth edition of Kassel art exhibition, Documenta, Austrian artist and architect group Haus-Rucker-Co produced this uncanny inflatable structure on the facade of the event’s principle venue, the Fridericianum. Drawing on the Situationist concept that one of the best means of engaging citizens is through play, the installation involved a transparent blow-up sphere containing a pair of palm trees and a steel-framed seating area for rest and relaxation, accessible via one of the museum’s upstairs windows. A decidedly whimsical sight.