No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

The ancient latrines of the Greeks, in all their public glory.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

Macabre astrological automaton clock dating to the late 1400s.

The only museum with its curator—and her pets—buried inside.

Where Venice's gondolas go for a tune-up.

This deconsecrated church has seen many uses, from a tobacco storehouse to a cinema.

A sinister pyramid in the Frari contains the heart of the famous neoclassical sculptor.

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

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

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

This Roman statue is missing a limb from when the Venetians stole it from Constantinople during the Crusades.

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

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.

Stare out over the lagoon and beyond from this 10th-century campanile on the island where the city of Venice began.

The small peaceful island off the Venice tourist circuit is where the city began more than 1,500 years ago.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

A brutalist gem towering over the heart of Milan.

A local student's chance encounter with Keith Haring led to the creation of one of Europe's largest murals.

Frank Lloyd Wright’s most iconic home dangles over a Pennsylvania waterfall.

Early prototype for Frank Lloyd Wright's Guggenheim.