A hilltop monastery on the Greek island of Hydra.

Where commuters walk through remnants of an ancient Greek necropolis.

Legend says this sacred tree was a gift from goddess Athena.

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

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

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

This unique building in the main square stands out among the city's typically Baroque architecture.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

This church is named for one of the most dramatic tales in the early Christian church.

Yemen's "Stone Palace" looks like it was carved right out of the tall stone column on which it is built.

Exploring the wilder, more passionate sibling of Erg Chebbi feels like discovering a secret sun-kissed planet from another galaxy.

One of the two original gateways into the Kasbah, this gateway is a nesting site for storks.

Morocco’s modern capital was once a haven for Barbary pirates, who went so far as to establish a republic of their own.

The courtyard of this small Marinid madrasa is a dazzling example of intricate Islamic architecture.

The oldest known university in the world is in Fez, Morocco.

Crumbling necropolis set high above Fez.

Traditional 11th-century outdoor tannery.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

World's largest film studio, where visitors tour the decaying sets that litter the harsh desert environment.

The other side is actually green.

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

Legend says this remote, “bottomless” lake was created by a curse.

This memorial to a murdered empress took 20 years to design, then spent 30 years hidden away in storage.