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

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

A more chill but no less fascinating version of the famous ancient archeological site.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

Earth's greatest purely vertical drop at 4,101 feet.

Abandoned ship reimagined as a street art canvas.

It's believed a castle existed at this site since the 12th century.

Dozens of musicians have planted trees in this Danish park, and donated songs to go with them.

This modernist tower was saved by a fraternity with a 500-year-old penchant for shooting at wooden parrots.

A failed attempt to control drifting sands yielded a gnarled sylvan wonderland.

A Danish fisherman spent 25 years covering nearly every inch of his home with tens of thousands of shells as a gift to his wife.

Former island in the Aral Sea used to be a top-secret Russian bio-weapons facility.

Once a bustling fishing port, this semi-ghost town is now more than 90 miles away from the shore.

The Avenue of Mausolea is a series of grand palatial tombs.

World's oldest and largest space launch facility, once a secret missile testing site.

Rusting ships sit in a desert where a sea used to be.

The eerie remnants of an ancient forest were hidden under the sand for centuries.

Ruins of two abandoned stations destroyed by the power they sought to harness.

Stay overnight in the world's most sleekly designed rabbit hole, free of charge.

Art Nouveau painter Alphonse Mucha spent 18 years creating these monumental paintings of Slavic history and mythology.

An explosion of natural color known as "the river that ran away from paradise."

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

This vintage car parts store is also a museum devoted to a squat little gem of automotive history.

Rare collectibles from automated musical instruments to 250 unique automobiles.