Fans of vintage Vegas, kitsch, and toy pony-based gambling now flock to a casino called The D.

According to legend, this ancient column contains healing properties.

These caves secretly held national treasures during World War II.

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

This small museum once served as a royal hunting pavilion for King Otto Friedrich Ludwig.

The attic of a four-century-old canal house hides a clandestine church.

This Ottoman-era church is hidden amid a busy tourist area.

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.