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

Go inside to really appreciate this 500-year-old technological masterpiece.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

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

Museum dedicated to literary greats of the Romantic Period is also the home in which Keats met his untimely end.

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

The final resting place of the poets Shelley and Keats.

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

Rome's semi-secret peephole vista is also a former Crusader stronghold.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

This stunning concert hall has become a symbol of Iceland's national recovery.

This colorful gate stands as an entrance to the walled city of Old San Juan.

Legend tells how a Spanish soldier disappeared from this isolated sentry box without a trace.

This bleach-white graveyard overlooking the ocean is accessed through a tunnel.

Everyone from Alan Ginsberg to The Rolling Stones has stopped by this classic dive bar.

This chapel on a cliff is renowned for its healing powers and was founded on the site of a supposed divine intervention.

How did a French journalist’s grave become the sexiest statue in the cemetery?

This monument marks the beginning journey of a wounded soldier's leg that ended up almost two states away.

Home of the only civilian casualty at the Battle of Gettysburg.

The beloved, war-tested mascot of a Union regiment graces their battlefield monument.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

A plaque immortalizes the spot where the early American spy said his famous last words: "I only regret that I have but one life to lose for my country."

The first piece of public art dedicated to LGBT rights.

Visit the monolithic tomb of America's most famous general.