Engineering

Camera cars and condom bikes built from scrap and one man's passion.

The "stairway to heaven" lookout tower was built to resist weather, arson, and the laws of physics.

The bridge's highly-contested plaque (once again) honors Confederate President Jefferson Davis.

This jewel of an engine is one of Northern England's finest surviving legacies of the Industrial Revolution, even catching the eye of Henry Ford.

This unique bridge physically lifts a piece of the road into the air to let boats pass by.

The world's tallest bridge is also possibly the most elegant.

A one-of-a-kind sundial at the Very Large Array honors a radio astronomy pioneer, incorporating the original piers from his breakthrough radio telescope.

This 47-story "M" needed 20 years to be completed

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

The former home of a railway legend and the site of a gigantic labyrinth.

This otherworldly church spire reaches up toward the heavens.

This frozen tunnel in central Alaska is both an engineering feat and a valuable climate classroom.

This centuries-old canal known as the Cuckoo Dyke has a staircase of locks suitable for a giant.

Double spiral staircases are not unheard of, but they are very rare.

The first tunnel to be dug beneath a river, repurposed as an art and museum space.

This restored 17th century "conduit house," often mistaken for a watchtower, actually supplied water to nearby Bolsover Castle.