More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

Pilgrimage site for star-crossed lovers.

One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

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

Go inside to really appreciate this 500-year-old technological masterpiece.

The yawning maw of this pagan visage is said to bite off the hands of liars.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

An unusual building on a "desolate hill" features the works of an Icelandic sculptor.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

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

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

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

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

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

This legendary city has been a tourist attraction for centuries.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

The hallucinogenic center of the ancient world.

A stunning gilt bronze relief denounced by Hitler as "degenerate art"—even though it was dedicated to the Nazi leader.

Hamburg's first legal sex work is relegated to a gated street that still does not allow pedestrian women.

One of the oldest wine cellars in Germany is now a restaurant beneath Bremen's town hall.