The Festival Centre Plaza also serves as host to an outdoor collection of sculpture, including the prominent stainless steel Environmental Sculpture (also known as Tetrahedra), by Bert Flugelman.
The space-filling truss of packed octahedra and tetrahedra was apparently first discovered by Alexander Graham Bell and independently re-discovered by Buckminster Fuller (who called it the octet truss and patented it in the 1940s).
Hessel also found Euler's formula disobeyed with interconnected polyhedra, for example, where an edge or vertex is shared by more than two faces (e.g. as in edge-sharing and vertex-sharing tetrahedra).
Sphatikam is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula Tetrahedron in Bottrop
The design is reminiscent of the Sierpinski tetrix: placing four half-size tetrahedra corner to corner and adding an octahedron in the middle, a full-size tetrahedron is formed; this process can be repeated recursively to form larger and larger tetrahedra.
Giant truncated tetrahedra were used for the "Man the Explorer" and "Man the Producer" theme pavilions in Expo 67.