The roof of this ancient mausoleum is made from a single Istrian stone weighing a massive 230 tons.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

Filled with goldfish swimming in a shallow pool of sea water, this ancient crypt is more wishing well than burial site.

Italian poet Dante Alighieri is entombed in this small mausoleum in Ravenna, and his hometown of Florence has never been too happy about it.

A medieval, mosaic-lined baptistry built by a heretical Christian sect.

Inside the small garden of two mid-century apartment buildings stands a centuries-old bell tower, separated from its original church and hidden from view.

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

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

This triumphal 16th-century arched gateway leads to the oldest street in Palermo.

This skeletal, unfinished Gothic church once housed a miraculous masterpiece by Raphael.

A striking memorial recalls thousands of Bolognese men and women killed fighting fascists in World War II.

This Renaissance palace features a unique architectural design and is now home to the Ferrara National Art Gallery.

Destroyed numerous times, this centuries-old bridge has always been rebuilt with its original design.

Time has been frozen at this station since the bombing in 1980—or so it was believed.

These pillars at the main entrance of this church are actually a hidden musical instrument.

Stuck in the arcade of Casa Isolani are three arrows of mysterious origins.

A brutalist gem towering over the heart of Milan.

A hidden bas-relief of a hare on a church main portal that brings good luck to the ones who find it.

The city of Parma's cathedral is home to one of the greatest illusionistic frescoes of the Renaissance.

A floating bridge leaning on barges allows pedestrians to reach the historical center.

It’s said this crypt was the setting for the tragic finale of the Shakespeare play.

The skull of this patron saint is kept in a shrine located in his hometown.

The seat of the Mantua bishop holds many secrets within its walls.