The rogue roots are gradually consuming some of the historic marble grave markers.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

Time travel with sweets across history at this research-based candy store.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

Famously misunderstood wonder of the ancient world

These markers note British stars of both stage and screen.

A square-domed symbol of resilience in the heart of the old Jewish Ghetto.

Believed to be the remains of the lost Temple of Minerva, this nymphaeum has been known by its misnomer to this day.

This unassuming bridge is most likely one of Michelangelo's unfinished masterworks.

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

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

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

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

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

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

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

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

An alchemist's “magic door” stands in the middle of a Roman park.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Architectural monsters are devouring this palace's every door and window.

2300-year-old Roman road connecting the empire.

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