A skyway, skybridge, skywalk, or sky walkway is an elevated type of pedway connecting two or more buildings in an urban area, or connecting elevated points within mountainous recreational zones. Urban skyways very often take the form of enclosed or covered footbridges that protect pedestrians from the weather. Open-top modern skyways in mountains now often have glass bottoms. Sometimes enclosed urban skywalks are made almost totally from glass, including ceilings, walls and floors. Also, some urban skyways function strictly as linear parks designed for walking.
Skyways in the Peachtree Center district of Atlanta
A Han Dynasty (202 BC – 220 AD) Chinese miniature model of two residential towers joined by a skyway
The Bridge of Sighs in Venice, Italy
The Hansasilta skyway crossing over the Itäväylä Highway in Itäkeskus, Helsinki, Finland
A covered bridge is a timber-truss bridge with a roof, decking, and siding, which in most covered bridges create an almost complete enclosure. The purpose of the covering is to protect the wooden structural members from the weather. Uncovered wooden bridges typically have a lifespan of only 20 years because of the effects of rain and sun, but a covered bridge can last over 100 years. In the United States, only about 1 in 10 survived the 20th century. The relatively small number of surviving bridges is due to deliberate replacement, neglect, and the high cost of restoration.
The Cogan House Covered Bridge, Pennsylvania
Schuylkill Permanent Bridge in Philadelphia, the first documented covered bridge in America
Covered bridge in Macon, Georgia, 1877
Pont de Rohan in Landerneau, France