This historic structure has been used as a mosque, a barracks, a prison, a school, and a bakery.

Where commuters walk through remnants of an ancient Greek necropolis.

This building displays the scars of the “Dekemvriana,” a dark time in modern Greek history.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

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

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

This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

Gladiators once walked this ancient, subterranean passage.

Since 1969, this restaurant has served up dishes typical of Istanbul's Greek diaspora.

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

A crushed gate and giant bronze head serve as a reminder of Greece's fight for freedom.

This striking sculpture of Icarus honors Greece's fallen flyers.

This narrow fjord-like bay is the largest ria in the Mediterranean Sea.

This truly palatial work of Communist-era architecture now sits crumbling on a Croatian beach.

This beautifully verdant lagoon is tucked below a massive volcano in a crater atop a black pebble beach.

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

Visit a surreal landscape so otherworldly NASA actually used it to train the Apollo 17 crew.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

This impressive working clock made of 16,000 plants changes its flowers twice a year.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

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