This curious, round temple is the oldest still-standing marble building in Rome.

This former school is now abandoned and a canvas for graffiti artists.

This letter written by Queen Elizabeth II in 1986 won't be opened until 2085.

It's believed Matilda Fitzwalter's life was the basis for the famed literary figure.

The stunningly blue waters of these beautiful caves also have a violent past.

This museum covers 10,000 years of Pre-Columbian Latin American history.

Makers and sellers of the original and finest York Ghosts.

The oldest Swedish built lighthouse still guides ships through the archipelago.

The largest caravanserai in Cyprus also includes amazing examples of Ottoman architecture.

This is the oldest Roman-made bridge in the city still existing in its original state.

These unique stained glass windows were designed by local children using a modern flair.

These hut foundations are believed to be the residence of Romulus, founder of Rome.

This museum is dedicated to the little known ancient Roman history of Vienna.

These small, triangular, colorful houses are a staple of Madeira Island.

These wooden pipes were crucial to providing water to Medieval Edinburgh.

This 19th-century ghost town offers a stunning view of Lake Michigan and a journey through the region's industrial past.

This museum is a full-size replica of an original church constructed during the 13th-century.

A memorial to a larger-than-life legend, inside a county that also holds Bunyan's death certificate.

This is the largest cemetery in Ireland and the first cemetery museum in the world.

These artificial caves crafted by ancient Romans were elaborate fish farms for moray eels.

This museum located in Fondi is also said to be the most haunted building in town.

This ancient market is often referred to as the oldest shopping mall in the world.

The “Sistine Chapel” of the Middle Ages merges 11th-century science and religion in wondrous hues.

This equestrian statue of Constantine the Great has been the subject of criticism for centuries.