red warning buoy, Duluth, MN, Minnesota, Lake Superior, View of Duluth Harbor and Aerial Lift Bridge on Lake Superior in Duluth.

Budapest, bridge, Hungary, Europe, Scenic aerial view of the Chain Bridge, the Danube (Donau) River and the capital city of Budapest at night.

skyline, Pittsburgh, bridge, PA, Pennsylvania, aerial, View of the downtown skyline of Pittsburgh and the Fort Pitt Bridge crossing the Monongahela River.

Pittsburgh, skyline, PA, Pennsylvania, Aerial view of the downtown skyline of Pittsburgh and Smithfield Street Bridge (truss-type bridge) crossing the Monongahela River.

Duluth, MN, Minnesota, Aerial Lift Bridge, 386 feet long, at Canal Park in Duluth.

bridge, Duluth, MN, Minnesota, Aerial Lift Bridge, 386 feet long, at Canal Park in Duluth.

Mackinac Bridge, Mackinaw City, MI, Michigan, Upper Peninsula, View of Mackinac Bridge, a suspension span bridge, crosses the Straits of Mackinaw in Mackinaw City connecting the Lower Peninsula with the Upper Peninsula of Michigan.

Mackinaw City, bridge, MI, Michigan, Upper Peninsula, View of Mackinac Bridge, a suspension span bridge, crosses the Straits of Mackinaw in Mackinaw City connecting the Lower Peninsula with the Upper Peninsula of Michigan.

Mackinaw City, MI, Michigan, Upper Peninsula, View of Mackinac Bridge, a suspension span bridge, in the evening crosses the Straits of Mackinaw in Mackinaw City connecting the Lower Peninsula with the Upper Peninsula of Michigan.

bridge, Duluth, MN, Minnesota, Aerial Lift Bridge, 386 feet long, at Canal Park in Duluth.

Mackinaw City, MI, Michigan, Upper Peninsula, View of Mackinac Bridge, a suspension span bridge, in the evening crosses the Straits of Mackinaw in Mackinaw City connecting the Lower Peninsula with the Upper Peninsula of Michigan.

bridge, Mackinaw City, MI, Michigan, Upper Peninsula, View of Mackinac Bridge, a suspension span bridge, in the evening crosses the Straits of Mackinaw in Mackinaw City connecting the Lower Peninsula with the Upper Peninsula of Michigan.

aerial view bridge bucolic connecting country