Designed to commemorate the founding of the first settlement in Delaware.

World War II-era bunkers are hidden under the beaches of this picturesque park, which is still scattered with wartime watchtowers.

A tunnel that brings more than a century of history to life from the deepest parts of the Niagara Gorge.

Niagara Falls holds a special place in Nikola Tesla's history, so they put a statue on it.

Secret refuge and museum of the Duke of Florence.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Breathtaking and huge 430 year old maps of Italy.

The remains of this 2nd-century Roman temple are incorporated into a modern building.

A monumental fountain in Rome features a large statue of Moses that has been criticized for centuries.

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

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

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

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

This large, circular tomb is the final resting place of the first emperor of Rome.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

One of Frank Lloyd Wright's greatest—and favorite—architectural masterpieces was almost lost.

Known as "Toronto's Flatiron."

This whimsical fountain pays tribute to Toronto's four-legged friends.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.