Most technology companies occupy leafy campuses on the outskirts of urban areas, but Amazon has grown up in the center of Seattle and drawn much of its innovative energy from its big-city location. The giant online retailer’s new headquarters doubles down on its commitment to urban engagement, creating a neighborhood of buildings, plazas, and public open spaces that connects seamlessly with Seattle’s existing metropolitan fabric. The most iconic element is the trio of glass spheres housing a multi-level botanical garden filled with 40,000 plants taken from high-altitude cloud forests from five continents.