Whenever people refer to the composition of the Silver Towers on Bleecker Street (two are owned by NYU and one is a middle-income co-op), they mention the buildings themselves ("bold concrete sculptural gridded facades") and the plaza containing "a giant sculpture by Carl Nesjar, a reinterpretation of Pablo Piccaso’s “Portrait of Sylvette”" (from I. M. Pei’s Silver Towers Could Become a Landmark). What is rarely mentioned is the unusual seating arrangement in the southeast corner of the superblock.
The seating area is "a broken spiral of concrete benches" (from the Landmarks Preservation Commission). If you stand at the edge of the inner most ledge of the spiral and utter "Ah" you are supposed to hear "Ah" as if you spoke it into an echoing microphone. Here is a photograph of a group of students trying this acoustic effect.