After the musical legend's death, his memorial was mysteriously graffitied in gold.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

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

This lab's maddening silence is good for business but bad for sanity.

Two thousand artifacts from around the world collected by one woman who loved to travel.

More than five miles of underground passageways.

The show pony of cave systems, Fantastic Caverns manages to live up to its name.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A beautiful geyser under environmental threat.

When you visit his grave, be sure to rub the Great Emancipator's nose for good luck.

The Magic House provides a beautiful and creative environment for curious youngsters to get their knowledge on.

Visit this playground of waterfalls, caves and sinkholes.

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

The longest navigable underground river in the United States is home to countless blind and albino animals.

Labor provided by Great Depression-era programs restored these 25,000 acres in Tennessee.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

All you ever needed or wanted to know about America's favorite whiskey, but not a drop to drink.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

Enormous lake at the bottom of a unique cave system.

A restaurant and lodge in northern Wisconsin which served as a clandestine hideout for John Dillinger and featured one of the most famous botched FBI raids in history.

The oldest certified bowling alley in the United States is in the basement of this century-old bar.

What may be America's largest classic video game arcade lurks inconspicuously in a Chicago suburb.