Pulled from the rubble of one of the worst modern tragedies, a steel crossbeam became a symbol of hope for New Yorkers.

The first piece of public art dedicated to LGBT rights.

The most confusing clock in New York.

The fanciest public restroom in New York City boasts fresh flowers, art, and a classical music soundtrack.

This legendary city has been a tourist attraction for centuries.

Ruins of a 13th-century fortress perched above a breathtaking Mediterranean bay.

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.

According to legend, this cavern holds the passage that Persephone used to travel to and from the underworld.

Monasteries on rock pillars, once accessible only by frayed ropes.

The hallucinogenic center of the ancient world.

Τhis feline monument commemorates fallen soldiers on a field that saw many, many battles.

The oldest cemetery of modern-day Athens blends the modern and ancient worlds.

A WWI fighter plane and turn-of-the-century penny candy shop are among the unexpected features of this Financial District building.

This ancient hydrological marvel is now the base of a modern outdoor cinema.

An ancient octagonal weather station named for the eight Greek gods of wind.

A beloved tribute to the Fab Four and the freedoms they inspired.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

What once sat in the world’s spotlight is today a largely disused ghost complex.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

The abandoned summer estate of the former Greek Royal Family.

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

A sharp sculpture made of thousands of pieces of jagged glass.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.