The sail of the first nuclear sub to circumnavigate the world.

Around half a million years ago, these magnificent columnar basalt cliffs were formed from cooling lava.

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

An architect's childhood fantasy treehouse made real.

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.

The first declared National Monument in the United States.

Four, 18-foot-tall badminton shuttlecocks lie scattered about the lawn of a Kansas City museum.

An ornate Art Deco tile mosaic representing Nebraskan life, both modern and prehistoric.

Haunted dolls, macabre artifacts, and more make up the collection of the “most haunted museum in the world.”

This once rural mansion now sits in the heart of the city.

A brick-paved former section of the historic coast-to-coast highway.

Home of Philip Johnson, one of the 20th century's most influential architects.

These mystical miniature houses bring a touch of magic to the New Jersey woods.

This little museum has an exhibit devoted to the elusive forest denizens.

An optical illusion found amid a logged redwood forest.

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

This massive redwood tree has a drive-thru tunnel carved out of its trunk.

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

A simple plaque remembers a California island massacre that claimed more than 100 lives.

Commonly referred to as the most photographed Victorian home in the United States.

This was once the largest four-sided clock in the world (yes, even bigger than Big Ben).