Standing just outside the fourth floor's main gallery, one can look out over the ledge of the monumental stair and see each previous flight cascading downward, lower and lower to the ground floor. It's a cool visual effect, but also provides a place of spectacle within the museum that's fertile ground for people-watching.
"People like to go to the Spanish Steps [in Rome] to, literally, watch each other," says architect Farshid Moussavi. "It's a very social place and museums today carry that role. It's not just about going to engage with art, but also going to engage with other people."
But housed inside that hulking staircase is a second, enclosed stairway that connects with each floor as well. While the design has been compared to a Mobius strip, Moussavi says it was actually a necessity of engineering. Designing the secondary stairway as a traditional ascending column simply wasn't possible.
"It would have taken up a corner of the building, which frankly we don't have because our corners are not vertical," she says. "The building leans as it grows vertically."
The result was one of the museum's most surreal touches, and one that makes visitors active participants in choosing how they'll climb or descend through the structure.
"It becomes a very fun way to engage with not only how you connect with the different floors, but also how you engage with the other people in the museum," Moussavi says, adding that the enclosed stairway can also be an intriguing venue for sound installation artists. "It's a space of encounter."