This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

Walk into an underground archeological dig, the site of the Roman Forum that was once the center of Valencia.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

Stunning Roman aqueduct used for 1900 years and still standing.

A hidden three-foot-wide house separates these two regal churches.

The best place in the world to buy tinned fish.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

An abandoned tuberculosis hospital said to be haunted by the patients who died within its walls.

This historic streetcar system has been running since the 19th-century.

A deer-headed statue that brings together a 12th-century legend and big wave surfing.

The corpse bride of Portugal.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

The stunning interior of this Gothic church is covered in ornate gold details.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

The site of Paul Revere's historic two lantern warning.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

The lecture hall where Alexander Graham Bell first demonstrated the long-distance phone call.

This home is steeped in history from, George Washington to George Corwin, High Sheriff during the Salem Witch Trials.

A quiet memorial marks the spot where the victims of the Salem Witch Trials were executed.

An architectural oddity hides in plain sight on this iconic London bridge.