This peculiar border irregularity is the only way to legally enter Russia without a visa.

Hidden in the hills is a mysterious stone structure, known only to a few.

A short hike into the mountainside forest reveals a decaying 1890s town.

Once the largest unsupported dome in the world, beating out the Pantheon and St Peters in Rome.

This abandoned caretaker's apartment is one of 13 left in the New York Public Library system.

You'd never know the houses at 23-24 Leinster Gardens were fakes—until you see the train tracks on the other side.

A temple to modernity, tucked away amid Barcelona's more well known museums.

The broken skateboards that became a poignant memorial to a murdered skater.

An adorably sweet display of sculpted Precious Moments figurines.

The effect of this ancient form of image projection situated atop an 11th century Moorish palace is thrilling.

An Italian vineyard invites religious pilgrims to stop by 24/7 to get their drink on, for free.

A once-magnificent collegiate church is falling into ruin.

Deep in a Polish forest, this collection of Iron Age megaliths still holds onto many of its ancient secrets.

Where the author wrote her beloved "Little House" books.

A memorial for a young woman and her ghost, which are claimed to have caused countless deathly shipwrecks.

A historic Georgian building and warm springs.

There is one corporation registered for every three square feet of space in this inconspicuous office building.

Remnants of a quarry company town still stand on the banks of the Wapsipinicon River.

Mounds, rune stones, and a 1,000-year-old church, left behind by Denmark's first two kings.

A massive Celtic cross secretly growing in an Irish forest.

The most powerful waterfall in all of Europe.

Elaborate hand-carved wooden clocks two brothers made in their spare time are on display at this handsome little museum.

At Monet's beloved home you can still see the Japanese bridge, waterlilies, and weeping willows that were the subjects of some of his most iconic paintings.

The ghostly remains of what was once the world's richest copper mine.