This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

Pompeii's less famous neighbor is still revealing her secrets.

This stunning concert hall has become a symbol of Iceland's national recovery.

The oldest hall in Iceland was written of in the Sagas and features a centuries-old escape tunnel.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

The oldest church in Iceland is one of the few to feature ornate decoration.

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

An encyclopedic collection of mammal penises.

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

Medicinal spa created with the discharge from a geothermal energy plant.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The fairy tale castle of the "fairy-tale king."

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

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

Macabre astrological automaton clock dating to the late 1400s.

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

Phil Mortillaro uses keys to bring art back to the Village.

Increasingly decayed figures stand as a powerful reminder of the human costs of Czech Communism.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

Allowing humans and fish alike to migrate from freshwater to saltwater and back again.