The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

The "Seinfeld" diner.

Try not to get slimed in Tribeca.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

A kaleidoscopic warehouse-maze of handmade neon signs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A terrific purveyor of natural history objects and curios.

World's largest collection of serial killer artwork and other macabre exhibits.

Non-profit time travel mart sells goods you would need for a trip through the fourth dimension.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

In 1953, a group of Wisconsin high school students helped build a hospital by collecting over a million pennies.

A historic ballroom host to famous performers from the big band era to 1980s rock.

Picturesque and haunting, these 160-year-old stone ruins on top of a bluff are the only remains of a settler's legacy.

Explore a real 19th-century lead and zinc mine at this immersive series of exhibits.

This park harkens back to frontier life in Wisconsin.

Exhibits from an island in Lake Michigan are preserved in this hand-built cabin museum.

These modest Midwestern formations are kin to Niagara Falls' impressive cliffs, more than 600 miles away.

A one-stop shop for all things snowmobile, started by a snowmobile-obsessed group of friends in Wisconsin.

A surprisingly large number of show waterski teams are located here in Wisconsin.

Prolific outsider artist Sid Boyum's concrete sculptures add whimsy to Madison's Schenk-Atwood neighborhood.

This rooftop sign has been confusing Milwaukee-bound airline passengers for decades.

The site of an ancient Mississippian settlement that appears to have flourished during the 10th to 13th centuries.