Reading through the timeline of sculptor Isamu Noguchi's projects is like a smack on the back of the head; there are so many playgrounds that never made it out of the maquette stage. They range back over fifty years to 1933 and though only one playground was realized during his lifetime [Piedmont Park in Atlanta], at least two awesome play sculpture designs--Slide Mantras, he called them--were completed soon after Noguchi's death in 1988.
Noguchi saw playgrounds as an ideal landscape for integrating sculpture into daily life, and the Slide Mantras are definitely sculptural. Abstracted mountains of stone featuring a spiral slide encircling a central stair tower were built in Miami and Sapporo. Miami's is Carrara marble, while Sapporo's is black granite.
From the look of rin's photoset on flickr, being in them creates spatial distortions similar to Richard Serra's Torqued Ellipses, which came ten years later. But while Serra's work is awe-inspiring and disorienting, Noguchi really meant for his to be fun. About the Sapporo slide, he said, "The completion of this sculpture will be when children polish it with their bottoms as they slide down."
Slide Mantra in Noguchi's Bayfront Park, Miami [bayfrontparkmiami.com]
Black Slide Mantra, Oo-Dori Park, Sapporo [sapporo-park.or.jp, image: hokudai]
Model for Slide Mantra and public projects timeline at the Noguchi Foundation [noguchi.org]