St. Augustine's record-setting narrow street was designed to protect against pirates.

The walls of America's oldest masonry fort famously "swallowed" cannonballs.

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

Five candy-colored villages on the Italian Riviera.

I-95's Tijuana-style celebration of kitsch at the Carolina border.

Charleston's historic city jail once held everyone from pirates to Civil War POWs.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

Eighty million natural history specimens call this gargantuan museum home.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

Northern Ireland's Brobdingnagian stepping stones.

A mysterious ancient elephant said to possess magic powers is now the symbol of a Sicilian city.

The world's most active stratovolcano is almost always erupting.

This amazingly preserved Doric temple was abandoned before it was ever completed.

This skeletal, unfinished Gothic church once housed a miraculous masterpiece by Raphael.

"Stairs of the Turks", a chalky white cliff eroded conveniently into stairs, allowing for easy pillaging.

Traversing steep Alpine slopes, this engineering marvel is one of the longest and highest funiculars in the world.

A historic observatory precariously perched at the "Top of Europe."

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

This now-deactivated naval base defended the Florida coast for centuries.

One of the only Florida forts to remain in the hands of the Union all through the Civil War still stands as a historic stronghold.