These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

A beautiful but toxic fountain of mercury.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

This winding road through an Italian canyon may be the most scenic drive in the world.

This Italian foot path winds through the mountains via 52 individual tunnels.

The plague quarantine island home to the alleged "Vampire of Venice."

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

The middle finger of modernity.

Europe’s oldest natural human mummy.

One of the world’s smallest bars, just 13 square feet, is brimming with speakeasy flair.

Filled with goldfish swimming in a shallow pool of sea water, this ancient crypt is more wishing well than burial site.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

The first memorial dedicated solely to the Black troops who fought for the Union.

You could be standing at the site of one of D.C.'s most fatal tragedies and not even know it.

The house where John Wilkes Booth conspired with his co-conspirators.

Site of the greatest known waterfall that ever existed.

An old vending machine serves up unpredictable beverages from its seemingly magical insides.

Stones speckled along Harris Avenue reveal hidden nuggets of the past.

This monument remembers the first Japanese Americans forcibly relocated during World War II.

Native American burial mounds? Giant gopher dens? No one knows what created the Mima Mounds.

The illuminated falls are a gem in North Cascades National Park.

An obscure waterfall that looks like something out of a fantasy novel.