This World War II relic let Allied pilots know they were entering neutral airspace.

This natural sea arch highlights Ireland's rugged coastal beauty.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

German-style coffee and cake, just like Oma used to make it.

A fearsome dragon clings to a corner of Munich's city hall.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

Sitting in the basement of a castle, the largest wine barrel in the world is bigger than most apartments.

This historic funicular system combines the old with the new while offering delightful views over the surrounding valley.

With over 10,000 lights, this engineering marvel lights up the city after dark.

This extraordinary, multi-pillared monument depicts the fascinating history of Georgia.

A cylinder monument with a spectacular vista commemorates a friendship that some say never existed.

Rock-hewn monastery complex with hundreds of cave structures tucked away into the mountainside.

Unusual building appears to be haphazardly built from randomly piled bricks.

Take respite inside this jaw-dropping church while climbing the volcano where Georgia's Prometheus was once chained.

You'll find just about anything in this funky Tbilisi flea market.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

The world's oldest known salt mine.

Along a coast that sees the annual migration of humpback whales, a geological formation that takes the shape of a whale’s tail.

The sister plane of the C-123 shot down during the Iran-Contra Affair has found a new purpose in retirement.

This portion of a lovely Belize beach is infested with (harmless) sharks and rays.

A massive underwater sinkhole made famous by Jacques Cousteau.

A galaxy of glowworms—larvae of a gnat—hides deep in the belly of these caves.