An ancient Greek monument and a Byzantine church coexist inside this cave.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

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

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

There must be a pun in this haystack somewhere...

Manhattan's lighthouse, erected at the insistence of the unsinkable Molly Brown.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

This Florida sinkhole hides a rainforest-like micro-environment in its depths.

This curious sculpture represents the perseverance needed to take to the skies.

The 1852 novel "Uncle Tom's Cabin" lends its name to a subway station, a street, and several shops on the edge of Berlin.

A plaque on the side of a building is a small tribute to the woman who invented an iconic Berlin fast food.

After local authorities changed the design, the building's architect, Le Corbusier, wanted nothing to do with it.

Designed to resemble foreign architecture, this mosque-looking structure was used to pump water to a royal fountain.

The "Prussian Versailles" that is as glorious today as when it was built.

A quaint Russian village in the middle of a German metropolis.

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

Inscribed on the gate are the names of 29 figures from the University's first five centuries.

This emblematic representation is said to bring the students good fortune.

A scattered trail of street art adds a pop of color to the city's stark structures.

Glasgow's memorial to the International Brigade volunteers from Great Britain who fought and died in the Spanish Civil War.

"Respectful to the dead, safe and sanitary to the living, dedicated to the Genius of Memory..."

Largest lake in Great Britain measured by surface area.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.