Surreal riveted sea forts once protected the Kent shores from German attack.

Northern Ireland's Brobdingnagian stepping stones.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

Harry Potter once visited this massive limestone cliff, which was carved by an ancient glacial river.

WWI hospital ship lost in a cyclone turns up on the coast of Fraser Island, where she remains rusted and forgotten.

Relics of Australia's convict past, and a modern scene of unimaginable horror.

This historic observatory contains the world's oldest refracting lens telescope.

Nine limestone rock stacks on Australia's "Shipwreck Coast."

This extraordinary geological oddity resembles human-made pavement.

The only pollutant in the clear blue water is sunscreen.

Giant topiary dog once played a role in a terrorist bomb plot.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

Sweden's "good old days" painstakingly re-created in a model village.

3,000 market stands in five former Zeppelin hangars.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.

Budapest's Communist-era statues, banished to the suburbs.

The oldest museum in Russia is home to a fascinating collection of nearly two million anthropological artifacts and anatomical curiosities.