A winding, blood-red tunnel of hardened lava navigable by foot.

Climb right into the heart of this colorful Iceland volcano.

An encyclopedic collection of mammal penises.

This modern monument to pagan belief looks like it was transported straight from ancient times.

Staves, storm-calling, and of course, necropants.

This is an amazing but little known tile mosaic mural that used to grace the lobby of an office building in 1958, but now can only be seen from the second floor of a Shoppers Drug Mart.

For decades, vendors have sold clothes once worn by American soldiers who stormed Italy in the 1940s.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

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

These hut foundations are believed to be the residence of Romulus, founder of Rome.

Legend has it that this bronze orb, which sat atop an ancient Egyptian obelisk, once held the ashes of Julius Caesar.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

A forgotten "city of water" underneath the famous Trevi district.

This ancient market is often referred to as the oldest shopping mall in the world.

A massive marble foot is tucked away in a small alley near the Pantheon.

A statue representing a lost Roman profession that was vandalized for centuries.

This statue is the only female representation of Rome's "talking statues."

This gallery commissioned by Cardinal Spada is known for its magnificent optical illusion.

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

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

This hidden alley near the location of Rome's first theater was the site of a curious miracle.

An 18th-century post box used to alert the church of sick and ailing foreign pilgrims.

A hospital where antique dolls are given new life.

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