In this historic region, homes and churches are carved into ancient volcanic rock formations.

While not Turkey's deepest underground city, this subterranean redoubt is the largest.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

This giant work of Cappadocian pottery includes a memorial for the artisan who created it.

This hidden gem is bathed in beautiful natural light.

This hunter-gatherer architecture is believed to be the oldest religious complex known.

A sacred lake with thousands of sacred carp and a biblical history.

Balanced on four stone pillars, this historic tower was the site of a tragic political assassination.

Standing proud atop a Turkish bluff, this Ottoman palace has retained its grandeur despite being abandoned for centuries.

Ottoman-era houses lovingly preserved.

Underneath this Byzantinian church lies a necropolis filled with ancient tombs and the ruins of previous churches.

This building has two facades of clashing architectural designs.

A striking symbol of the Bulgarian capital.

"Unity, Creativity, Beauty."

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

A sculpture of a beloved local figure, who tipped his top hat to everyone he passed on the streets of Bratislava.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

This giant radio telescope would be a rusting ruin if it hadn't become such a beloved relic.

The facade of this 16th-century building is decorated with carvings of 300 seashells.

A Spanish artist builds his own castle.

The Roman city was the birthplace of various emperors and is home to one of the empire's most impressive architectural feats.

This centuries-old tower hosts endangered bald ibis mating pairs and looms over a pristine beach.

Dead weights honor the dead of Portugal's fishing industry.

At night, bats patrol this magnificent 18th-century space in search of book-eating pests.