To build a folly is essentially to do something a second time, something at an inopportune moment. That something is always the memory of something forgotten, about which we can paradoxically say "There it is again."
Follies were misunderstood, purposeless constructions. They were often only small, extravagant gestures in a garden, easily whisking off the imagination to distant lands, a sort of time capsule built to awaken the memory and induce surprise in passers-by. They marked locations, organized secondary paths in a park, or simply predicted the arrival of better times—a demarcation, a sacred spot, a mysterious trail, a hill whose tragic rocky nature begged for a tower, a party, or the arrival of summer.
“It is demonstrably true that things cannot be other than as they are. For, everything having been made for a purpose, everything is necessarily for the best purpose.” — Professor Pangloss
Normally after the design was built, you would find places for the art to be located and then you would go out and select the artist that you wanted. That is historically, the traditional way to go.
But this time, someone else was calling the shots. A planning official, basically, who comes along and says, “We want you guys to work with an artist.” And the architects are like, “Sure of course.” But then the official goes—“No, you don’t quite understand. We want you to use an artist as a co-equal member of the design team.” That is, the artists are going to have just as much control as the architects. It was really unheard of.