Richard Dattner's Play Cubes, 1976

The Japanese climbing structure reminds me of the interlocking cuboctahedra designed by architect Richard Dattner in 1976-1977, which he patented and called 'playcubes'. His goal was to provide a flexible and low-cost solution for small playgrounds; estimating in 1977 that a standard installation would cost around $7500.  They've been the subject of an interesting series of blog posts (to which Dattner himself responded!) at the blog daddytypes (here and here), and a set is still in place at the South Park playground in San Francisco.

First image from Richard Dattner Architect: Selected and Current Works----Master Architect IV (The Master Architect Series, 4), Second image from Patent No. 3,632,109: Richard Dattner, Modular Recreation Unit and Combinations Thereof , third and fourth are of the South Park installation, from Susan Solomon's website.