The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

An astounding collection of medical specimens, including bits of President Lincoln.

An extraordinarily ornate museum in San Diego holds wondrous anthropological treasures.

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

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

A popular swimming hole that hides one of America's most deadly diving spots.

A collection of Witchcraft artifacts and occult paraphernalia started by the leader of the Long Island Coven.

Tour the sci-fi-esque reality of governmental disease management.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.

Quite simply the largest tree in the world (by volume).

The world's longest known cave system.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

A monument to the art of slicing people open.

The world's only international cryptozoology museum is host to an unrivaled collection of mysterious objects.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

An emerald-green grotto just a short trip from Austin.

On the Oregon coast there is a natural hole that seems to be draining the sea.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

A crumbling hospital from the 1850s on Roosevelt Island.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

A museum within a museum, devoted to history's most questionable medical devices.