Ancient ruins hidden underneath a modern luxury hotel.

An ancient Egyptian obelisk is now used to commemorate fallen Italian soldiers.

A sculpture serving as an homage to Pope John Paul II.

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

Plaques on its facade commemorate the Tiber's most destructive deluges.

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

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

An ancient Roman temple first dedicated to an emperor's wife is now a church.

Though the case is scorched and the buttons half-melted, this hardy handheld gaming device can still run a game of Tetris.

The 28-foot granite map plots the locations of 40 theaters in New York City.

Museum celebrating the ocean, with the largest wunderkammer dedicated to sea exploration.

A colorful piece of contemporary art cheerfully clashes with Lyon's historical architecture.

This hidden garden boasts amazing views of Lyon.

Lyon's miniature version of the Eiffel Tower was built as a statement in support of French secularism.

Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.

One of Mexico's least-visited archaeological sites is tucked away inside a theme park.

An ancient system of freshwater caves filled with animal bones, including that of species long-extinct.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

More than 50,000 gannets claim the cliffs of Bonaventure Island.

Montreal's giant farmer's market is a foodie's best friend, especially in the winter months.

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

Small ship votives hang from the vaulted ceiling of this port-side church with a Latin inscription on the wall.

A historic Montreal market that was the city's agricultural hub for over century.