Hear the quietest sound from across the dome.

Eighty million natural history specimens call this gargantuan museum home.

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

Browse through a century of this principality's first popular export.

San Gennaro, the patron saint of Naples, greets pedestrians between these narrow city streets.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

These hut foundations are believed to be the residence of Romulus, founder of Rome.

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

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

This curious, round temple is the oldest still-standing marble building in Rome.

The "Great Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

The yawning maw of this pagan visage is said to bite off the hands of liars.

The once forbidden "secret cabinet" of erotic art from excavations of Pompeii and Herculaneum.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

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

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

A forgotten "city of water" underneath the famous Trevi district.

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

Plaques on its facade commemorate the Tiber's most destructive deluges.

A detailed pachyderm supports Rome's smallest Egyptian obelisk.