This cave holds a surprisingly colorful variety of geological oddities.

These molds for fiberglass statues have formed an eerie, accidental sculpture park.

Robots, lasers, and whoopee cushions, oh my!

"World's largest scrap metal sculpture" stands in an outdoor sculpture garden in the middle of Wisconsin.

A bizarre house filled with an astounding array of collections.

An 18th century fountain and two columns are all that remains of Rome's forgotten river harbor.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

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

A wunderkammer of curious objects and intriguing art nestled within a hub of ancient Roman sites.

A burial vault located under Tiber Island in the middle of the Italian capital.

Remnants of a 4th-century church with vivid medieval frescoes and ancient sarcophagi hide beneath this old basilica.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

The mystic whose incorrupt corpse still attracts the faithful.

A small cell adjacent to this church was once the bedroom for a renowned saint.

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

The charred, dead skeleton of an oak tree is said to have consoled a dying 16th-century Italian poet.

The first Russian Orthodox church in the Catholic city of Rome in almost a thousand years.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

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

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Amateur taxidermy museum known for its large collection of white squirrels.

Gambling, boozing, and yodeling animals cover the walls of this dive bar cum natural history museum.