This natural sea cave hides a small wonderland of natural turquoise beauty.

A well-preserved network of cavernous tunnels have spent silent centuries removing Toronto's waste.

One of the last few period-correct, hand-operated canal locks in the country.

There is beauty and history in the ruins of this former company town.

A 30-foot stack of piano keys memorializes one of the greatest keys players in jazz history.

This unique collection collects pieces of art etched into thin pieces of stone.

Mussolini gave Cincinnati a bronze statue of Romulus and Remus suckling at a wolf's teats.

There are more than 4 million bricks inside this unofficial Lego museum in a former middle school.

Medical history museum featuring a lovely doctor's office from the 1800s.

These sub-farmland caves are home to a majestic stalactite known as the "Crystal King."

An abandoned relic of the city's failed experiment with below ground transit.

Over a thousand feet beneath the Detroit streets is a subterranean metropolis few are allowed to enter.

The collection of ceremonial and cultural objects spans many countries and hundreds of years.

The world’s largest Masonic temple was saved by the White Stripes.

A quaint miniatures museum that turns its focus towards the lives of Americans in a simpler time.

A lavender labyrinth so large it’s visible on Google Earth.

This freshwater spring fills with 10,000 gallons of water per minute.

Controversial tribute to the heavyweight champion boxer who grew up in Detroit.

A painted-over wall in Detroit originally built to segregate a black community from an adjacent white development.

Berry Gordy Jr.'s old home was the original headquarters of Motown Record Corporation.

One man's attempt to create an artistic wonder on a run-down block in Detroit.

The bones of an old zoo crumbling in the shadow of a new one.

A wacky two-story folk-art assemblage of carved and found objects, with lights, motion, and sound now in need of financial support.

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.