ALABAMA: Noccalula Falls is a 90-foot waterfall with its own gorge trail. Visits can explore an aboriginal fort, a pioneer homestead, Civil War carvings, and caves nearby.
ALASKA: The Northern Lights, also known as the aurora borealis, is a spectacular natural light show caused by the collision of solar wind with particles in our atmosphere.
ARIZONA: Step aside, Grand Canyon. The Wave rivals the famous landmark's beauty with its colorful, undulating sandstone rock formations carved by time and erosion.
ARKANSAS: The Ozark region will take visitors' breath away with its steep-sloping plateaus, drastic drops in elevation, and wooded mountains as far as the eye can see.
CALIFORNIA: Sequoia National Park contains some of the tallest trees on Earth. The giant sequoia and redwood trees are hundreds of years old and grow over 300 feet high.
COLORADO: Pikes Peak, at the front of the Rocky Mountain Range, was christened "America's Mountain" for its part in inspiring the words to "America the Beautiful."
CONNECTICUT: Like other New England states, Connecticut is a stunning place to stop and see the fall foliage. Fun fact: The trees along the Connecticut River, from the mouth of the Long Island Sound to East Haddam, hold the foliage the longest.
DELAWARE: The Great Cypress Swamp on the Delmarva Peninsula features the northernmost natural stand of bald cypress trees in the US. It's home to 73 species of birds.
FLORIDA: The Everglades, a watery wilderness formed by trees and marshland, is the largest subtropical wilderness in the US. It's worth a trip after visiting Walt Disney World.
GEORGIA: The quartz monzonite dome for which Stone Mountain Park is named stands nearly 1,700 feet tall. It got a not-so-natural upgrade: A carving depicts three Confederate figures during the Civil War: Stonewall Jackson, Robert E. Lee, and Jefferson Davis.
HAWAII: At the Kilauea volcano, magma comes flying out in solid chunks of ash rather than seeping out as lava, making the volcano not only beautiful but also dangerous.
IDAHO: The "fire rainbow" is a rare phenomenon that occurs only in certain areas, like Idaho, where the sun can reach more than 58 degrees above the horizon. Ice crystals in the atmosphere capture the light of the sun and refract all the colors of the rainbow.
ILLINOIS: Lake Michigan is the only one of the Great Lakes located entirely in the US. While it also shares waterfront with Michigan, Indiana, and Wisconsin, the lake provides drinking water for 8.5 million Illinoisans, making it an important natural resource for the state.
INDIANA: On the shores of Lake Michigan, Indiana's sand dunes rise nearly 200 feet high. They're the result of the last great continental glacier's retreat about 14,000 years ago.
IOWA: Clouds that look torn from a Van Gogh painting, called asperatus clouds, roll over the plains. First photographed in Cedar Rapids in 2006, the clouds dissipate in 15 minutes.
KANSAS: One of the largest salt deposits in the world is buried 650 feet underground. Its formation dates back 275 million years, when the Permian Sea dried up.
KENTUCKY: Mammoth Caves is an expansive cave system with more than 400 explored miles of caverns, chambers, and subterranean passageways.
LOUISIANA: The bayous of Louisiana are so much more than swamps. These wetlands are active waterways with native animal and plant life. At 375 miles, Bayou Bartholomew is the longest in the world.
MAINE: A hot spot for tourists, Acadia National Park has pristine views, hidden pathways and trails, and the tallest mountain on the US Atlantic coast.
MARYLAND: A barrier island shared between Maryland and Virginia, Assateague Island is famous for its wild horses. Local folklore says a shipwreck brought the horses there.
MASSACHUSETTS: The intrigue and beauty of Walden Pond are praised most notably by Henry David Thoreau in his book "Walden," which is based on his experiences living there.
MICHIGAN: Lake Superior surrounds Isle Royale National Park, home to free-roaming moose and wolves. Lake Superior could hold all the other bodies of water in the Great Lakes.
MINNESOTA: Boundary Waters Canoe Area Wilderness spans over one million acres in the northern part of Minnesota. The area is mostly water interspersed with tiny islands that formed as the glaciers of the last ice age retreated and deposited huge boulders.
MISSISSIPPI: The Mississippi River, which effectively splits the country in half, is both beautiful and dangerous. Inclement weather can cause devastating flooding in the area.
MISSOURI: Onondaga Cave is one of the most beautiful in the country, with dripping stalagmites and "lily pads" formed by mineral deposits in the water.
MONTANA: Glacier National Park features rugged peaks, pristine forests, glacier-carved valleys, and sparkling waters. It's a hiker's paradise, with more than 700 miles of trails.
NEBRASKA: Chimney Rock National Historic Site is a geological formation left over from the erosion of the bluffs at the edge of the North Platte Valley. The spire rises 325 feet from the base and is composed of layers of volcanic ash and Brule clay.
NEVADA: Named for the brilliant sandstone formations that burn red like the sun, Valley of Fire State Park was formed 150 million years ago by shifting in the sand dunes.
NEW HAMPSHIRE: The highest peak in the Northeast, Mount Washington stretches 6,288 feet into the sky. In fair weather, its summit offers views of Maine, Vermont, Massachusetts, Quebec, and even New York.
NEW JERSEY: The Garden State's crown jewel remains its 130 miles of coastline, spanning from Sandy Hook to Cape May. The white-sand beaches draw hundreds of thousands of visitors each year.
NEW MEXICO: The White Sands National Monument is the world's largest gypsum sand dune field, encompassing 275 square miles of glistening white sands.
NEW YORK: Niagara Falls flushes 3,160 tons of water over its falls every second and produces over four million kilowatts of electricity, which is shared by the US and Canada.
NORTH CAROLINA: Along the Blue Ridge Parkway through the Appalachian Highlands is one of the most ecologically diverse areas in the world: home to 100 varieties of trees, 1,600 plant species, 54 mammals, and 159 species of birds.
NORTH DAKOTA: The Little Missouri National Grasslands feature colorful and unspoiled badlands, rugged terrain eroded by wind and water, and both long and short prairie grasses.
OHIO: Follow the hemlock-lined trails of Hocking Hills State Park and you'll find cascading waterfalls, deep-recessed caves, and cliff views that will steal your breath away.
OKLAHOMA: Seawater flooded the Sooner State millions of years ago. When the water eventually evaporated, thick salt deposits remained and formed the Great Salt Plains.
OREGON: Thor's Well is a huge saltwater fountain powered by the Pacific Ocean. When the surf is up, water shoots upward from the bowl and then drains back into the opening.
PENNSYLVANIA: Ricketts Glen harbors 22 named waterfalls, each cascading through rock-strewn clefts in the hillside. The highest, Ganoga Falls, drops 94 feet.
RHODE ISLAND: Often compared to the cliffs of Ireland, the 200-foot-tall Mohegan Bluffs offer panoramic views of the Atlantic Ocean. Visitors must climb down 140 steps and over yards of boulders in order to reach the beach, but it's worth the trip.
SOUTH CAROLINA: The lush marshes on Hunting Island provide the best sunset views. The Vietnam War scenes in "Forrest Gump" were filmed along Marsh Boardwalk.
SOUTH DAKOTA: One of the world's richest fossil beds can be found at Badlands National Park. Ancient mammal species, like the saber-toothed cat, once roamed here.
TENNESSEE: For two weeks every summer, a special species of fireflies gathers in Great Smoky Mountains National Park for mating season. The fireflies blink in unison.
TEXAS: A pink granite dome rising above Enchanted Rock State Natural Area formed a billion years ago, when a large pool of magma buoyed above the Earth's surface, cooled, and slowly turned to granite. It's an exfoliation dome, meaning it has layers like an onion.
UTAH: Arches National Park is a red, arid desert, punctuated with over 2,000 natural stone arches, soaring pinnacles, massive fins, and giant balanced rocks.
VERMONT: The Green Mountain National Forest is within a day's drive for more than 70 million people, so locals as well as tourists can enjoy its watercolor-like landscapes.
VIRGINIA: A road trip down Skyline Drive shows off all that beautiful Shenandoah National Park has to offer, including wildlife and wildflowers that bloom all year round.
WASHINGTON: Olympic National Park contains glacial mountains, beaches, and rain forests in its one million acres. The famed Hall of Mosses is blanked in a lush green canopy.
WEST VIRGINIA: The aptly named Mountain State is the only state that lies completely within the Appalachian Mountain region. You can hike all of the Appalachian Trail's 2,184 miles, passing through West Virginia and traversing scenic, wooded, and pastoral lands.
WISCONSIN: The Apostle Islands National Lakeshore is an archipelago of 21 islands that dot the waters of Lake Superior. Frozen waterfalls hang inside its sea caves.
WYOMING: Yellowstone National Park's Grand Prismatic Spring, the largest hot spring in the US, features a brilliant rainbow produced by bacteria that lives on the perimeter.