Mysterious library of an infamous financier and spiritual seeker.

This massive mushroom has spent centuries eating its way across a huge swath of Oregon.

The trunks of 3,000 year-old trees lurk beneath the surface of this crystal clear lake in Oregon.

A rugged lava field dotted with molds of the ancient pines that were growing when the volcano erupted.

Planes, trains, and automobiles have all been sunk as attractions at this Illinois diving spot.

A hidden grotto on the grounds of the Kane County Government Center.

Small and slightly hidden, the American Writers Museum is preserving the legacy of America's finest authors.

Eclectic collection of rare and beautiful stones in a historic home.

A replica viking ship from the Chicago World's Fair is still in dry dock in an Illinois park.

A century-old hotspot for jazz, frequented by everyone from Charlie Chaplin to Al Capone.

This unauthorized stone mermaid was secretly carved out of public stone before being permanently preserved.

An antiquated German apothecary on Chicago's North Side.

A Bibliophile's Dream.

A lush green oasis in the middle of Chicago.

Over thousands of years, this slot canyon was carved out of the bed of an ancient lake.

A remnant of the last Ice Age, this lake is surrounded by fascinating rock formations.

This solitary gravestone is separated from the rest in Appleton, explaining why local legends continue to surround it.

According to the legend, this strikingly beautiful hill has miraculous healing powers.

Robots, lasers, and whoopee cushions, oh my!

These Great Lakes sea caves accessible by boat in the summer turn into temples of ice reachable by foot in the winter.

A bizarre house filled with an astounding array of collections.

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