Its interior is adorned with some of the best examples of early Christian mosaics.

This hydrochronometer was invented by a Dominican monk and is a prime feature in this garden.

Also known as the Square Colosseum, this building is a prime example of fascist-era rationalist architecture.

This gallery commissioned by Cardinal Spada is known for its magnificent optical illusion.

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

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

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

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

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

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

A fairy tale castle in modern Rome.

Jesus' footprints and the first catacombs in the world.

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

The final resting place of the poets Shelley and Keats.

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

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

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

Architectureal fantasy quarter of Rome.

This delightful little museum is dedicated to only one thing: pasta.

The Italian revolutionary's legendary wife is portrayed on horseback waving a gun and holding her child in this memorial on the Janiculum.

According to local folklore, this Roman sepulcher was once a throne for the Devil.

Rome's first modern graffito is all that is left of a peaceful protest from the 1970s.

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.