One of the largest helium balloons in the U.S. is a 112-foot ginormous orange.

This enormous World War II relic is one of the largest wooden structures in the world.

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

This dramatic rail curve was once the target of a failed Nazi attack.

The remains of a religious colony, its amusement park, zoo, and baseball empire.

Its impressive still-working beam engine is a thing of beauty for engineering history fans.

Nature is leading a successful mutiny on this century-old freighter.

The charming collection celebrates a small Ohio village's Finnish roots.

Fortified homes of highland warriors that are still in use today.

Britain’s longest ancient monument, this great 8th century earthwork was built to mark the boundary between what would become England and Wales.

Hidden in the shadow of a rocky fortress is one concubine’s long-forgotten legacy.

An abandoned suspension bridge on the Falkland Islands is crumbling into the water.

A bizarre house filled with an astounding array of collections.

A futuristic hovertrain is parked unceremoniously alongside a nondescript road.

This beautiful example of Victorian engineering is the oldest water-balanced funicular anywhere in the world.

A town church once nearly submerged by the damming of a river is now hauntingly visible as the water recedes.

A mental health hospital dating back more than 139 years, now features a museum.

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

Edison's cast-in-place concrete houses were a failure, but way ahead of their time.

There aren't too many operational funiculars around, but Pittsburgh has two!

No one knows who's responsible for decorating this tunnel with stuffed animals, but the people love it enough to protest their removal.

The oldest funicular in Lithuania has been climbing this steep hill since 1931.

This steep cable railway has been hoisting passengers in the heart of Québec City for over a century.

A favorite with sightseers, this Norwegian funicular provides easy access to a stunning view of Bergen and its environs.