In the 1980s Frei Otto's favourite game was to show visitors to the Institute for Lightweight Structures in Stuttgart-Vaihingen an aerial view of the university campus and to say to them: "Show me where my institute is."
The visitor's gaze would wander over the trees and several institute buildings and suddenly come across the roof of a grey tent, towering upwards, but hardly visible. That is the institute building at Pfaffenwaldring 14 and is a 1:1 model of the German exhibition pavilion at the EXPO '67 in Montreal.
The long search and sudden surprise were the best praise Frei Otto could wish for: his building is "part of nature, a part of the whole!".