The walls of America's oldest masonry fort famously "swallowed" cannonballs.

The eerie remnants of an ancient forest were hidden under the sand for centuries.

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

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

An architect's childhood fantasy treehouse made real.

A beautiful geyser under environmental threat.

Two mammoth statues inspired by equally tall tales lure tourists to this roadside attraction.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

This massive redwood tree has a hole in the base big enough to drive through.

A mysterious dark-skinned Christ statue has been this town's religious center for centuries.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

A wild west cemetery in Tombstone, Arizona, provides a window into the Old West.

An old saloon in the West filled with history, and according to some, a few dozen ghosts.

Sleep where gangsters fell amidst smoke and flame, with nary a bullethole to show for the legendary struggle.

Make a wish at what might be America's only Catholic shrine to a sinner.

This amazingly preserved Gold Rush town is a historian's dream.

A classic carnival ride that was carved to be untouchable.

L. Frank Baum wrote part of the "Wizard of Oz" series in this wooden Victorian beach resort.

The small town of Poulsbo in Washington state is the next best thing to the Kingdom of Norway.

A magical sanctuary of mythological statuary.

Railways may have forged this quintet of lovely tunnels, but now they are open to hikers.

Cascading outward, this waterfall creates the appearance of a flowing veil.

This expansive bridge in the Canadian wilderness was originally just built for friends.