The oldest active mini golf course in the U.S. has an elegant Art Deco style filled with lush tropical plants.

Craggy concrete faces are hidden in the walls of this artificial cave along the San Antonio River.

The remains of an ancient Roman city are hidden underneath Bologna's beautiful public library.

The San Marino-Rimini railroad was short-lived but this tunnel once provided shelter for hundreds of refugees during World War II.

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

High in the clouds of San Marino sits an ancient tower with some curious prisoner graffiti.

Where members of the Crossbow Corps of San Marino demonstrate their skills.

An Albanian monument to the Communism that nearly crushed the country is now a crumbling wreck.

In the heart of Tirana, this underground nuclear bunker has been transformed into a museum.

Decorated with a staggering 1,380 ladybugs, the installation has turned what was once a grim, forgotten nickel mine into a landmark and a statement.

A monastery considered a state-protected cultural monument of exceptional importance, founded in the 14th century by Serbian King Stefan Dečanski.

A UNESCO-protected spiritual seat of the Old Serbian Kingdom and Empire.

This lonely minaret with an unusual decorative symbol is all that remains of a historic Ottoman mosque.

A 14th-century Serbian Orthodox church that was once converted into a mosque under the much-disfavored Ottoman Empire.

A historical puzzle lies at the origins of this structure.

Despite time, colonization, and the brutal New Mexican heat, these Pueblo ruins still stand.

The remains of a historic ranch house that witnessed the Civil War battle dubbed the “Gettysburg of the West.”

A town honors its legacy of traditional American Indian pipe carving with one gigantic pipe.

This large midwestern cavern features impressive rock formations and an underground waterfall.

The Midwest's reigning king of surplus stores is full of nothing you need and everything you want.

A collection of pianos and more guaranteed to delight anyone interested in music history.

This symbol of peace is appropriately positioned overlooking the Pacific Ocean.

Dolphins, ancient clams and hundreds of waterfalls make this one of the world's top tourist destinations.

These phallic stone spires once served as Tolkien's Paths of the Dead.