The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

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

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

A monument celebrating the idea of reaching inaccessible places.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

True to its name, this little house presents like a dollhouse, and surprising details are revealed with a quick peek through the window.

The "All-Seeing Eye of God" symbol on this library is a clue to one of the many former lives of this building.

A monument marks the location of the first successful steamboat demonstration.

Immortalized in bronze, this frazzled student will be glued to his screen for centuries.

A swaggering, monumental souvenir of the most extravagant party Montreal’s ever thrown.

From lefty Jewish gathering site to hip cultural site in just 80 years.

Two thirds of this Montreal neon icon has survived to flash another day.

A massive Montreal stadium that has seen nothing but trouble since its inception.

Every year, the colorful murals of Montreal get a complete makeover.

One of Canada's oldest museums, the beautiful Redpath has been serving up Natural History and Ethnography since 1882.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

A beautiful example of 18th-century engineering still standing tall.

This eerily opulent residential museum is home to a haunting local legend.

The tunnel that runs beneath this former inn was once a hiding place for enslaved people seeking freedom.

Wisconsin's most celebrated export gets the royal treatment on I-94.

This small-town opera house has appeared much more in national culture and history than its charming setting might suggest.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.