The Minneapolis system of skybridges & indoor walkways, called Skyways, connects 80 blocks of downtown and runs for more than 8 miles (13 km). Each bridge is unique in its design. It's hard to choose just one, but my fave might be the ones connecting to the IDS Crystal Court. Downtown St. Paul has a comparable system but all bridges there have the same design.
A winter view:
Other views available here: http://www.phototour.minneapolis.mn....?terms=skyways