This derelict superstructure was a very important warning system for the Soviet military.

A reconstructed medieval gateway that was the magnificent entrance to the capital city dating back to 1037.

Flying high over the small island of Zákynthos is a giant tribute to the mainland.

A magical, if a bit tacky, 1960s castle conjures up medieval fairytales and Greek mythology.

This wrecked ghost ship has been rusting on a Greek beach since the 1980s.

The oldest olive tree in Greece has been bearing fruit for at least 2,000 years.

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

This legendary city has been a tourist attraction for centuries.

Hidden in a secluded Greek cove is a pristine beach marred only by the rusting smuggler's hulk stranded on its shores.

A miniature train-ride through Slovenia's largest cave system.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

These natural cliffs look like they are a part of an old castle complex.

A striking symbol of the Bulgarian capital.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

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

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

This town named for the ancient God of War is home to fewer than a thousand people, but it's the birthplace of the Greek Revolution.

These sea caves are the source of Xigia Beach's distinct aroma.

The first declared National Monument in the United States.

A fitting attraction for the corn capital of the world.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

Windblown rock formations in an ancient Roman quarry.

A gorgeous stone viaduct crosses over a bucolic valley.