These wondrously illuminated caverns extend under the mountains of the Fukushima Prefecture.

The crumbling remains of the first Black-owned and operated hospital in Kansas City.

Curious cave that stays a cool 56 degrees all year long.

The flower-shaped temple in Virginia aims to transcend the boundaries of the world’s religions.

This abandoned prison castle has become an imposing gallery of graffiti art.

A nursery specializing in strange and beautiful succulents and cacti.

This ancient octopus-like tree was saved from destruction thanks to shady reporting.

A 19th century library favored by Edgar Allan Poe and H.P. Lovecraft, known by locals as "the Ath."

Free public park and gardens filled with peacocks and peahens.

A mysterious light floating in the trees of Arkansas may be a piezoelectric effect.

The thousands of shades on display — some toxic, others impossibly rare — are a library of more than just color.

A large instrument played by the wind.

A 120-year-old legend concerning an empty circular patch in the North Carolina woods.

A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

One of the oldest living oak trees in the Southeast.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

Hidden beneath a bridge, this waterfall is known for the large amounts of graffiti painted on its base.

A giant 400-acre preserve in North Florida for displaced wolves.

Yale University's home for rare works, including the mysterious Voynich Manuscript.

This free, take-a-book shop seems like a trick but isn't.

A ghost town at the airport is now a refuge for blue butterflies.

The longest living non-clonal organisms on Earth.

These eerie outliers of the lightning bug family glow a mysterious blue color.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.