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

Underneath one of the region's most historic roads lies the home of Plato's successor.

One of the best-preserved medieval streets in Europe.

Gladiators once walked this ancient, subterranean passage.

One of the greatest collections of coins in the world is housed in the former mansion of an archeological pioneer.

A sprawling collection of books and manuscripts about ancient Greece that would have put their famed libraries to shame.

The ruins of an ancient Roman tomb hidden in the basement of a trendy clothing store.

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

The ruins of an abandoned medieval city where the last Byzantine emperor was crowned.

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

The oldest cemetery of modern-day Athens blends the modern and ancient worlds.

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

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

The hallucinogenic center of the ancient world.

The oldest surviving botanic garden in the United States.

Designed as a place for patients to take in the scenery, this tower has a dark history.

An elderly widow still operates the incredibly detailed model railroad she and her husband built by hand.

Accessible only by boat, this centuries-old island fort never saw troops or combat.

The most photographed house in Maine looks good enough to eat.

This tiny patch of arid sand sits in one of the greenest states in the United States.

The highest point in Maine is a grand gift to the state citizens that also happens to be one end of the Appalachian Trail.

The eccentric mansion of one the most popular horror authors of modern times.

This tall Massachusetts folly got its name thanks to all of the purple prose its vistas inspired.

A mysterious stone embedded at the base of a historic Boston building.