One of seven Jewish catacombs in Rome and one of only two open to the public.

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

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

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

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

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

Known for centuries as the famous Roman emperor's burial place, this monument is actually something else.

This statue is the only female representation of Rome's "talking statues."

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

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

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

This ancient market is often referred to as the oldest shopping mall in the world.

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

In Rome’s Jewish ghetto, a 200-year-old bakery still makes the neighborhood’s historic sweets.

An eerie, derelict amusement park in Berlin.

This little replica of Lady Liberty provides a bit of NYC in a Japanese city.

Hamburgers are intensely proud of their tunnel beneath the river.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

A much-loved sculpture depicting the hero of a 1956 anti-Soviet uprising.

A giant glider—designed by the father of the Rubik's Cube's designer—now soars within a shopping mall.

A plaque bearing the names of those who dedicated themselves to protecting Budapest's Jewish population during World War II.

This sculpture honors the man who was known as the "Righteous Among the Nations."

The holes in this wall provide a glimpse into Jewish life in Budapest, both past and present.

From cartoon characters to tiny tanks, a guerilla sculptor's little bronze statues are hidden throughout the city of Budapest.