This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

These caves secretly held national treasures during World War II.

A Byzantine-era church hidden in a wooded area below the Acropolis.

150 or so scrounged-up lamps, chandeliers, and lanterns light up this alley in central Athens.

Legend says it was constructed with the destroyed pillar of an ancient Greek Temple.

Equal parts record-breaking temple to consumerism and bizarre fun park, it's more than you think it is...

A Borgesian work of art that may blur the line between fiction and reality a little too convincingly.

A whimsical sensor instrument for Minneapolitans to play on their walks to work.

Illegal drag racing two stories beneath Chicago’s streets.

Fragments of architectural wonders from around the globe are embedded in the newspaper building's walls.

Residents of Fremont in Seattle have considered it the center of the universe since the 1970s.

A wall of chewing gum moonlights as collective art.

This half-ton piece of the Alps sits at the base of the CN Tower.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

A rare chance to get up close and personal with a 13-mile ribbon of ice near downtown Juneau.

The fifth-longest natural arch in the world, and the longest outside China.

It's safe—and permitted—to walk across these twin natural sandstone arches.

The unusual burial monument of Arizona's first governor.

This quirky UFO-shaped curiosity is often mistaken for the airport’s control tower.

The former site of an all-but-forgotten colonial landmark is now remembered by an often overlooked bas relief.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.

The site of Paul Revere's historic two lantern warning.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.