This collection of odd proofs of concept is like taking a walk through the imagination of a Victorian engineer.

A verdant 17th-century-style garden hidden along Edinburgh’s Royal Mile.

The colorful stairs are made with marble from the world's major quarries.

Hidden beneath a beautiful overlook you’ll find the history of the city depicted in comic strip format next to a pay toilet.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

Fortified medieval tower house with lovely roof garden.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

The pile of books behind the dignified writer gave the statue a most undignified nickname.

According to tradition this is the oldest church in Venice, but its actual age is a mystery.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

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

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

This unusual lava tube spouts seawater during high surf.

A controversial memorial at the place where Captain Cook met his violent end.

The southernmost point in the United States is a beautiful place to look at but a deadly place to wade in.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

A cooled lava flow from the Haleakalā volcano formed these surreal-looking columnar basalt structures.

The air force base preserves its scars from the Japanese attack on Pearl Harbor.

This narrow coastline trail through the dense Kauai wilderness is among the most beautiful and dangerous in the world.

Submerged lava formations create incredible waterworks.

The unique collection includes bronze cast handprints of some of America's most famous astronauts.

A building so large that it has its own weather.

An underwater statue of Christ blesses the depths off Key Largo.