This stucco building in North Africa was the first American-owned property on foreign soil.

The final resting place of the great navigator, or maybe his brother.

A marvel of Byzantine engineering under the streets of Istanbul.

What was once a unique system of urban elevators is turning into a mechanical ruin.

Every equinox this Maya pyramid puts on a spooky ancient light show.

The final resting place of Christopher Columbus - or possibly someone else.

The oldest standing Byzantine church in Athens is tucked within a monastery in the middle of an upscale shopping district.

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

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

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

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