On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

Floating swimming pool within a moored vessel.

Berlin's natural history museum houses the world's largest mounted dinosaur and the late beloved polar bear Knut.

A take-out restaurant that only serves cuisine from countries with which the United States is in conflict.

This floating cinema brings new meaning to the phrase "going out" to the movies.

The largest earthwork effigy in the world.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

A beautiful geyser under environmental threat.

Finale of "William Tell Overture" can be heard as drivers pass over grooves in the road.

Roman ruins top white travertine terraces formed by ancient hot springs.

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

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

In the middle of an extremely unforgiving and desolate high desert is the most secret military facility in the world.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

America's most famous piece of self-built architecture.

An underwater city for the dead.

A rare view of a preserved Victorian science museum.

The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

This whimsical Oz-themed park had a wonderful impact on the surrounding neighborhood.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

These azure waters were thought to lead to the Mayan Underworld.

A giant Troll lurks under one of Seattle's oldest bridges.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.