It's the most anticipated debut of a Seattle building since the first visitors rode elevators to the top of the Space Needle 56 years ago. Welcome to the Seattle Spheres -- Amazon's trio of steel-and-glass buildings crammed with more that 400 different plant species, which will officially open on January 30. Take a tour of the one-of-a-kind-building where the workers of the online retail giant will chill in a rainforest.