The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

Ancient ruins hidden underneath a modern luxury hotel.

A modern sliver of architecture in Roma.

The studio built by fascists in the hopes of "reviving the film industry" with the occasional propaganda film opportunity thrown in.

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

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

A copy of the famous statue can be found in this Florence piazza, along with one of the most breathtaking views of the city below.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

Secret refuge and museum of the Duke of Florence.

Drink wine handed out through a window as part of an age-old tradition.

Art and armour fill every inch of this rich kid's Italian villa.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

According to tradition this is the oldest church in Venice, but its actual age is a mystery.

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

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

Go inside to really appreciate this 500-year-old technological masterpiece.

Venice's "Island of the Mad."

A spectacular Petrine Baroque summer palace commissioned for Catherine I by Peter the Great.

The Guardian of Tallinn.

This dizzying tower was built to better broadcast the 1980 Moscow Olympics.

The oldest continuously operating pharmacy in Europe.

A forest park outside Tallinn full of architectural and artistic curiosities.