One of the bridges connects a distant parking garage and health club, boasting that is the longest pedestrian bridge in the world. When the atrium idea reaches the perimeter, the landscape itself becomes the equivalent of Portman's downtown atriums. The ravine in the dense landscape is the dominant image of Ravinia, in the manner of Portman's hotel atriums where the building itself becomes a neutral background. The atrium, and its virtual counterpart, the private garden, are new building types in the new city. Skybridges and tunnels are common in large cities.
Circulation is layered to reduce conflicts, make space secure, or provide better service.
But in Atlanta, bridges are only for the project, connecting the various parts of the City Within the City. In the office park, like Ravinia, interior movement is also separate from the exterior, but the skybridge becomes a garden path, a pedestrian bridge over a lake, or a trellis-covered walkway in the private interior garden, reserved only for the employees or temporary residents of the City Within a City. The parking lot is now the most experienced urban space in the new city. In the old city, the street is the primary urban space, providing a continuous public realm and weaving the city's parts into a complete and legible whole. The typical pre-World War II American Street, whether Main Street or Elm Street, forms a continuous space made up by the facing buildings or the landscape of trees planted in the space between the curb and the sidewalk.