A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

This medieval Estonian tower provides access to a series of tunnels that have been home to soldiers, punks, and fine art.

A stone marker and sculpture in the city of Riga stake a claim for the very first community Christmas tree.

A black cat protests the City Guild in Riga's Old Town.

3,000 market stands in five former Zeppelin hangars.

Flamboyant architecture from the turn of 20th century.

The capital of the Cayman Islands is a center of offshore banking, but gets battered by blistering hurricanes.

Send a postcard while vacationing with Satan.

This popular tourist cave was ignored for almost 200 years before being mined into an attraction.

This home of a taxidermy hoarder is among the grandest and most singular of historic English estates.

Semi-precious Blue John stones have been mined in this cavern system for centuries.

Seat of the Duke and Duchess of Devonshire for centuries.

A popular day's outing in Bovington consists of watching military tank driving practice.

The world's only managed flock of mute swans was established as a factory for monk meat but is now an adorable sanctuary.

This tiny town features a tiny town that acts as a 3D snapshot of the town during the 1950's.

In 1943 the British military took control of this village, telling residents they had to leave temporarily. The villagers were never allowed to return.

This exclusive resort has completely covered a tiny Balkan island in a 5-star warren of guest rooms.

A tiny church on a man-made island in the Adriatic.

A curious cave church carved into the face of a cliff.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

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

A stratovolcano located in the south of Iceland, with a long history of charted activity and a rich mythology attached.

This elegant arc of a waterfall marks a religious turning point.

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