The 420-foot tall mixed-use Phoenix Observation Tower is poised to become the headline destination in the Valley of the Sun in Arizona. The design by BIG has been nicknamed "The Pin," and resembles a metaphorical pin marking a location on a map. The 360-degree observation deck has been redefined as a descending spiral inside a sphere. Three glass elevators take visitors from the shaded public plaza and retail shops at its base up to the top for an open-air view of the mountains. Solely by using changes in slope, the spiral is gently divided into flexible spaces for exhibition, retail, and recreation.