This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

The tallest outdoor elevator in Europe rockets passengers on a dizzyingly precarious ride to the top of a mountain.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

Physicist’s epitaph provides final confirmation to a career of turmoil.

A wonderfully strange collection of 500+ stuffed frogs doing people things.

One of the best-preserved Roman amphitheaters is still used today, but for less brutal events.

The monument honors the mountaineers who were part of Europe’s best anti-Nazi forces.

This one-time health resort was used by aristocrats around the world.

One of the biggest Buddhist stupas in Europe, hidden from most locals.

An eclectic art form practiced by untrained masters is celebrated at this museum in the heart of Zagreb's old Upper Town.

This scale model of our solar system hid in plain sight for years before a physics team sought out all the planets.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

One of the highest emergency huts in the world has been waiting almost a century to give imperiled climbers a place to lie down.

For centuries no one knew there were hundreds of bones and precious artwork hidden beneath this Swiss church.

Traversing steep Alpine slopes, this engineering marvel is one of the longest and highest funiculars in the world.

A historic observatory precariously perched at the "Top of Europe."

The alpine falls where Sherlock Holmes apparently met his demise can actually be visited.

This amazing pedestrian suspension bridge in the Swiss Alps would give Indiana Jones nightmares.

Half of a house.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

A vast city of the dead, where the deceased outnumber the living by more than a million.

A 1920s home transformed into an immersive art experience, where every room is a portal to another realm.

The restored and active Victorian-era final resting place of San Francisco.

This 24-acre park offers a place for meditation in the midst of Sedona's iconic red rocks.