A winding, blood-red tunnel of hardened lava navigable by foot.

Iceland's tribute to its thankless civil servants.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

The spectacular subterranean collection includes dazzling minerals, including a piece of "kryptonite."

This abandoned hospital is one of the most haunted places in Costa Rica.

This neon blue river gets its color from a unique mix of bacteria and volcano minerals.

On this stunning Scottish island, you can walk in the footsteps of dinosaurs.

Islanders once used this dramatic, otherworldly landscape to hide their cattle from Viking raiders.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

These fantastically named natural pools look like something out of a Scottish myth.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

A railroad tunnel that, upon its completion, was considered one of the engineering marvels of the modern world.

This "floating railway" is one of the world's oldest monorail systems.

The national park was once a plantation estate.

The United States Capitol's former columns still stand.