A larger-than-life house of cards stands outside the house of a former fashion designer.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

Long-abandoned art nouveau baths beneath Milan's Piazza Oberdan.

Stone dwellings of the Mahos, Fuerteventura's original inhabitants

One of only two exposed meteor impact craters in the United States

A kaleidoscopic warehouse-maze of handmade neon signs.

When this 400-year-old fountain fell into disrepair, officials covered the mess up with what looks like a giant soup tureen.

An expansive collection donated by an heirless nobleman formed this admission-free civic museum.

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

The "Great Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

A magnificent waterfall is also home to the remains of a Roman hydraulic engineering system.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

A Nesting Doll of Churches.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Likely the world’s only place where you’re meant to skate on top of cars.

One of the best-preserved pieces of DDR propaganda in Berlin.

A hidden, morbidly fascinating cemetery deep in the forest.

A historic fire call point.

The site where a plot to assassinate Hitler was planned—and its conspirators were executed—is now a powerful memorial to the German resistance during World War II.

You've probably seen these distinctive orange-tiled columns on the big screen.