A replica of the first public theater built in California.

The California capital city once stood 10 feet lower than it does today.

I Street Bridge is the heaviest swinging center bridge in the United States.

Art Deco stylings conceal the true nature of this bridge.

Outsider art or homage to aliens?

A sculpture dedicated to Napa Valley's oldest mineral water company.

California's own majestic geyser is powered by a subterranean volcano.

The fossilized remains of ancient California redwoods.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

The people of Padua pledged to construct this church if the city was spared from destruction during World War I.

One of the world's oldest working clocks is curiously missing the Zodiac sign of Libra.

Something's missing between the arcades of the Palazzo della Ragione in "the city of the three withouts."

The tomb of the mythological founder of Padua is not hidden in some obscure crypt, but stands right in the middle of the city square.

Built to repay the sins of the father, this church is home to one of the most valuable works of Western art.

This old medieval prison tower has been a site of astronomical research for more than 250 years.

The incorrupt tongue of the patron saint of lost things is venerated in this basilica.

One of the largest squares in Europe contains an entire artificial island.

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

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

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

The remains of an ancient Roman city are hidden underneath Bologna's beautiful public library.

A large statue of Pope Gregory XIII in Bologna was disguised as Saint Petronius to avoid destruction.

The mummified relic of St. Antoninus.

Renaissance hospital featuring a rotating door into which unwanted babies were dropped.