A marvel of Byzantine engineering under the streets of Istanbul.

A series of waterfalls and pools that flow through the 'Ohe'o Gulch and into the ocean.

The famous aviator's final resting place is a study in natural beauty.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

This natural Icelandic fissure allows divers to swim right between two volatile tectonic plates.

Infamous marsh filled with toxic waste, World War II-era London rubble, and dead mobsters galore.

Hell on Earth is actually a small town in Michigan where anyone can be mayor for a day.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

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

Museum dedicated to the terror regimes of Hungary.

The final resting place for the remains of 143 Habsburg royalty.

Macabre astrological automaton clock dating to the late 1400s.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

This sword isn't waiting for a king to pull it out. It was placed there by a saint.

A dismembered holy head stares out from her beautiful reliquary at the St. Dominic Basilica.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

The middle finger of modernity.

The famous sculptor left his mark on this Italian wall in an internationally protected example of street art.

Whimsical artist house in the New Jersey woods.