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

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

A controversial art piece that harkens back to local folklore.

A curious memento mori hangs in the magnificent Cathedral of Segovia.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.

Where commuters walk through remnants of an ancient Greek necropolis.

Gladiators once walked this ancient, subterranean passage.

The ruined doorway is a portal to the building's turbulent and torturous past.

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

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

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

These hut foundations are believed to be the residence of Romulus, founder of Rome.

A monumental fountain in Rome features a large statue of Moses that has been criticized for centuries.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

An ancient Egyptian temple in the middle of Madrid, Spain.

A haven for book enthusiasts across the street from Retiro Park.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

This outdoor mural is one stop on a walking trail that weaves art and history together to tell a tale of local history.

This sinkhole in the Arizona desert is filled with carbonated, arsenic-rich water

Beneath a Virginia City bar is the entrance to an abandoned gold mine.

The now-overgrown beach resort was once frequented by Yugoslav military elite.