Infrastructure

This dizzying span over the ancient Algerian city was once the highest suspension bridge in the world.

The F1 Mexican Grand Prix circuit goes right through the middle of this old baseball stadium.

The world’s tallest outdoor lift stretches along the stone pillars that inspired the floating mountains in the movie “Avatar.”

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

This gem from the industrial age helps visitors and residents alike traverse hilly Stockholm.

An elegant sandstone stairway built by the WPA still connects two neighborhoods in Akron.

Climb atop one of the world's longest and heaviest trains for an unbelievable journey across the Sahara Desert.

This giant boulder is sandwiched between apartment complexes in upper Manhattan.

With its webbed walls and bright red coloring, Calgary's iconic bridge looks like a finger trap puzzle stretched across the river.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

This ancient stone bridge is a hub for daredevils.

The end appears to be nigh for the world's fourth-longest floating bridge.