An engineering masterpiece, or “Scheme of Madness?”

This 1800s former railway tunnel is now part of a heritage walking trail.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

An ancient Roman temple first dedicated to an emperor's wife is now a church.

St. Francesca Romana, patron saint of drivers, resides in the church she founded.

After spending more than a century on the ocean floor, this shipwrecked column is finally resting atop solid ground.

This scenic waterfront swimming pool is the longest salt water pool in North America.

The "plyscraper" is the world's tallest building made predominantly out of wood.

Two graffiti towers stand like ghosts of Vancouver's World War II-era defensive outpost.

This conservatory allows a little bit of the tropics to thrive in the middle of a major Canadian city.

At just six feet two inches deep, it is said by Guiness and Ripley to be the world’s narrowest freestanding office building.

This historic Victorian hotel has a scandalous history of affairs and murder.

A famous hotel houses an impression collection of mini dioramas and giant doll houses.

Clusters of huge boulders in the Australian Outback.

The UFO capital of Australia is the outback’s answer to Roswell.

The ruins of a once prosperous power station have become a mouldering seaside gem.

Visible from both land and sea.

An abandoned marine theme park has created a difficult experiment in dolphin rewilding.

One of the few places in the world home to living stromatolites.

Alien rock formations grown from the sands of an Australian national park.

A micronation of epic proportions.

A massive concentration of algae is responsible for this lake's pink hue.

Living fossils in this remote Australian bay provide a glimpse of what Earth may have looked like 3.5 billion years ago.

This Australian beach is composed of tiny shells.