Almost everyone has heard of Mount Rushmore and the Statue of Liberty. It seems they've stolen the show, attracting millions of visitors every year looking to expand their knowledge of American history. While the two most-visited monuments are impressive, there are more than 120 national monuments in the United States, some of which receive only a tiny fraction of guests as the iconic frontrunners.

Perhaps these places are less popular because people don't know about them. Luckily,  this list highlights some of the least-visited national monuments in America. There won't be a pop quiz at the end, but the unforgettable stories these places tell visitors about history are sure to stay in their memories and get them thinking about planning a visit to check things out for themselves.

9 Aniakchak, Alaska

The Aniakchak National Monument and Preserve is only reachable by boat or seaplane, which explains why it is the least-visited of all U.S. monuments. That said, those who can check out this magnificent piece of land most definitely should.

An enormous crater formed over 3,500 years ago by a collapsed volcano sits in an untouched wilderness without a facility or marked hiking trail to be found. Among the beautiful scenery is Surprise Lake, a glacial and spring-fed body of turquoise water that feeds the Aniakchak River. There's also an abundance of rock formations carved over hundreds of thousands of years by volcanic activity, providing adventurers with a diverse array of terrain to explore.

Related: Alaska Is Better In The Summer, And These Cities Promise The Vacation Of A Lifetime

8 Fossil Butte, Wyoming

People are familiar with Devil's Tower, America's first National Monument, but an equally impressive spot lies on the opposite side of Wyoming near the border of Utah. Over the years, thousands of plant and animal fossils have been uncovered in a prehistoric lake, some dating back over 50 million years! Fossil Butte National Monument contains the most expansive collection of Eocene Epoch fossils in the world, and visitors will be amazed as they learn how different the earth looked long before humans existed.

7 Booker T. Washington, Virginia

Booker T. Washington was born into slavery on a tobacco farm in Virginia during the 19th century. When he was freed at the age of nine, Washington became one of the United States' most influential intellectual thinkers of his time. Without the privilege of education early on, Washington worked the rest of his life to ensure he did all he could to change this for African Americans, whose oppression did not disappear when slavery was abolished.

Today, portions of the farm Booker T. Washington grew up on have been preserved and designated a national monument. Several buildings filled with agricultural artifacts teach guests about tobacco farming during the 19th century. More importantly, visitors can walk the historic grounds and learn about Washington's life and achievements, underscoring his legacy as an early civil rights leader dedicated to making life better for people through education.

6 Russel Cave, Alabama

Early settlers utilized their natural surroundings in ways human beings have since left behind. Russell Cave serves as a reminder of how far humanity has come during its short time on earth. The limestone cave is one of the earliest rock shelters in the country, its use by Native Americans dating back over 7,000 years.

Several archaeological digs have uncovered important artifacts left behind by these early people, including pieces of pottery, spear and arrow points, and remains of humans and animals. Visitors to Russell Cave have the opportunity to stand in a spot once occupied by early humans and ponder what life might have been like before the existence of modern conveniences.

Related: Rediscovering Alabama: Why This State Should Be On Your Bucket List

5 Gila Cliff Dwellings, New Mexico

The Gila Cliff Dwellings in New Mexico are another remarkable example of early civilization's ability to thrive without modern technology. Just as the Native Americans in Alabama did at Russell Cave, the peoples in the Gila Wilderness utilized the caves on their own as temporary shelters, deciding in the 13th century to make the place feel more like home.

The remarkable landscape of the Gila Wilderness is majestic by itself, a diverse mix of forest, grassland, and rock formations. A short, slightly strenuous hike on the Gila Cliff Trail takes guests up human-made stairs to a series of impressive Mongollan structures still standing today, some with upwards of 40 rooms! Visitors can step inside the ancient dwellings and peer out the same windows as the Mongollan people did hundreds of years ago.

4 George Washington Carver, Missouri

George Washington Carver was the first African American to have a national monument dedicated to honoring his achievements in the United States. Carver is best known for creating peanut butter, but the chemist invented hundreds of things during his lifetime that shaped agriculture throughout the country and the world.

The George Washington Carver National Monument educates visitors on the scientist's voracious curiosity about his natural surroundings during childhood, which went on to shape his impressive accomplishments as an adult. A nature trail goes through restored woodlands and tallgrass fields decorated by statues of Carver as a boy and a man.

Related: Let's Talk Missouri: Why The Ozarks Aren't The Only Thing Worth Visiting In This State

3 Alibates Flint Quarries, Texas

Flint-laden bluffs sit high above the Canadian River Valley in Texas. For over 13,000 years, Native Americans utilized the resource to craft tools necessary for survival. The highly coveted Alibates flint comes in an array of visually striking colors, including reds, oranges, greens, and blues, and spread through many Plains Indian tribes throughout history.

Visitors join a knowledgeable guide on a hike through the area, where they will walk the path the Native Americans took to the source of flint high in the red bluffs. Petroglyphs dot the boulders throughout the Alibates Quarries, and the ruins of an Antelope Creek village illustrate how early settlers used the land around them to survive. Archaeologists have uncovered several artifacts in the area, many of which are displayed at the visitor center.

2 Fort Union, New Mexico

After the United States acquired New Mexico, military heads established garrisons across the state to ensure protection against various threats. Fort Union was one of these structures, and the wind-beaten remnants of the military post are a testament to America's determination to safeguard its resources.

Today, guests can learn about all the ways the U.S. army utilized Fort Union during the 1800s, walking away with a sense of respect for the people who lived in the area during the time. Living history programs bring the fort's story to life, and rangers have instituted many outreach programs to draw in visitors to the underrated monument.

Related: Fort Monroe: Why You Should Visit The Largest Fort Ever Built In America

1 El Morro, New Mexico

It's starting to seem like travelers are sleeping on New Mexico in general, or at least its national monuments. A unique blend of history is open for exploration by visitors at the El Morro National Monument. The remains of an ancient Pueblan village built during the 13th century sit atop a sandstone mesa. The structures in the town continued to be used by travelers of all kinds over the years for shelter. Many people left inscriptions on the walls that are still visible today.

Next: This Is What The Devil’s Postpile National Monument Is Known For, And Why It's Worth Visiting