On La Gomera, "Silbadors" communicate in a 4,000-word language of whistles.

2300-year-old Roman road connecting the empire.

Replicas of Apollo's leonine stone guard cats still line a sacred row in Greece.

Giant marble phalluses on the sacred island of antiquity.

Religious structure known for its sculpted details.

This fairy-tale castle would make Dracula (who is said to have been imprisoned there) jealous.

Once the legendary capital of the Dacian Kingdom, this city has been reduced to mere ruins.

Nine centuries-old fortresses guard the walls of this medieval Romanian city.

A medieval church built up to defend its village.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

A 5,000-year-old city in Peru holds the remains of a stunning set of astronomically-aligned pyramids.

The highest tropical mountain range in the world is in Central Peru, home to a vast array of exotic and quirky plants and animals.

The outside of this exposed Moche pyramid is covered with striking colorful adobe friezes.

The larger of two volcanic peaks rising out of the crystalline waters of the Caribbean.

Come for the springs; stay for the mud bath.

After Christopher Columbus died, his son built a fancy house to rule from.

The oldest colonial fortress in the Americas was once the home and later prison of Christopher Columbus.

Built in 1512, the oldest cathedral in the Americas.

This geometric feat is a testament to the Incas' mesmerizing architectural abilities.

Now containing the bones of the actual conquistador, instead of someone else.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

Colonial architecture meets urban art in this sprawling open-air gallery.

Light still pours into the ruins of this ancient Islamic observatory.

The remains of an ancient city-state along the Silk Road.