This ancient structure appears Roman, but was constructed during the 16th century and was utilized until 1911.

This building served as the first customs house in modern Greece.

These ancient ruins hide in plain sight next to a dessert shop.

A historic building houses one of the most important archaeological institutes in Europe.

Public water fountains built during the Ottoman Era still stand throughout this seaside town.

This church is dedicated to the patron saint of seafarers.

This building was once the most magnificent mansion in Nafplio.

Europe's official "zero-level," the equator of elevation.

The secret wartime bunker built on the platforms of an abandoned Tube station.

Fragments of architectural wonders from around the globe are embedded in the newspaper building's walls.

Get fishing gear and craft beer at this restaurant on the pier.

The oldest standing structure in downtown San Diego.

A magnificent, reportedly haunted mansion built for a composer by Spiritualists.

Ruins of a 13th-century fortress perched above a breathtaking Mediterranean bay.

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

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

This Underground station has been a popular filming location for decades, even before it closed.

The ruins of an ancient fortification wall sit in front of and underneath this boutique hotel.

A tiny Greek Orthodox church from the Ottoman era hides on a busy city street.

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

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

The ruins of this ancient fortification wall sit in the middle of a quiet, residential intersection.

This seaside sanctuary was once one of the most important religious sites for women in ancient Greece.

Only open for two days a year, this church links ancient Greek and modern Christian celebrations.