This immaculate and historic water garden culminates in a massive stone dining table with an inset fountain for chilling the wine of the Cardinal's guests.

A naturally beautiful, seemingly bottomless deep blue spring.

According to the local folklore, the myriad colors of this lake are the result of a lovelorn wizard's blunder.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

A crumbling hospital from the 1850s on Roosevelt Island.

This abandoned seaside fortress is now simply an imposing ruin being taken back by nature.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

Once America's longest-manned military fort, now an abandoned hulk.

The haunting, dilapidated remains of a former poorhouse on Staten Island's Greenbelt.

Unrepaired walls from a 1920 anarchist bomb attack.

This vacant church in the Financial District was once the heart of New York's first Syrian immigrant community.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

Mirrors and glass shards cover every inch of this arrestingly beautiful mosque.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

The thousands of shades on display — some toxic, others impossibly rare — are a library of more than just color.

This modest plaza in Moneygall, Ireland has cashed in on its distant connection to the U.S. president.

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

This Hungarian stilt village is built in a lake that never freezes over due to the power plant that that uses it as a cooling pond.

The second-largest Jewish temple in Bulgaria was deserted after World War II, seized by the communist government and then abandoned again.

Religious perseverance and cultural coexistence manifest in an architectural gem that multiple wars couldn't topple.

Southern Italy's spinning top village.

Despite being pillaged and destroyed a number over times down the centuries, this historic church still sort of stands.