Did you know that the United States has over 2,600 National Historic Landmarks? They serve as official markers of the country's history and not just any old site will do. To be awarded this esteemed designation, the property or place must have a significant national impact by way of an event, person, time period, design or archeological finding. From the well-known to the surprising, here we've selected 30 places with a story to tell. 

Ivy Green is a historic house museum that honours the life of Helen Keller, who was born here in 1880. Both deaf and blind, Keller learned to read and communicate through sign language and Braille and became the first deafblind person to earn a bachelor's degree. Keller was an advocate of blind rights around the world and wrote 12 books, including her 1903 autobiography The Story of My Life. 

The Eastern State Penitentiary was once the world's most expensive prison. One of its most famous previous inmates was the notorious mobster Al Capone – you can even visit his cell. However, these days, nearly 200 years later, this massive and rundown complex serves as a historic museum by day and spooky haunted house at night. Discover the eeriest abandoned attraction in your state here. 

While you might think Florida is just about the theme parks, the truth is the southern state is chock-full of beautiful natural spots and historic sites. One visit to Crystal River and it's easy to see how it got its name. The water here is a gorgeous glimmering turquoise from afar and absolutely crystal clear up close. The 61-acre archeological site is one of the longest-inhabited areas in Florida. Plus, it's one of the best places to see manatees in the wild.

Located in Asheville, the Biltmore Estate offers a glimpse at a life of pure opulence. This sprawling Gilded Age mansion estate is the largest privately-owned residence in the United States with the floor space measuring a whopping 178 square feet (16.6sqm). While no one currently resides in the late-1800s home, the family operates it as a visitor attraction with guided tours of both the interior and the gorgeous gardens. Discover more of America's beautiful historic homes you can visit here too.

Oak Alley Plantation has lived many lives over its 200-plus-year existence and though it started as a sugar plantation, today it's dedicated to educating visitors about the history of slavery. The 28-acre property gets its name from the double-row of oak trees that create a canopied path that leads up to the house (though the trees existed before the building). While its landscaping and architecture helped Oak Alley get its designation, it also earned a spot thanks to an enslaved gardener who pioneered a technique in the mid-1800s that made growing pecan trees commercially viable.

While we've listed the Hoover Dam as being in Nevada, it actually straddles the state line with Arizona. Miraculously, this concrete piece of architecture and design that stretches over the Colorado River was built during the Great Depression thanks to much blood, sweat, tears, and money – it cost $165 million at the time, around $2.6 billion today. Although it's named after President J. Edgar Hoover, it was initially dedicated to President Franklin D. Roosevelt. 

Originally made of petrified wood and other natural tone materials, this building served as a tourist site called Stone Tree House during the 1920s. It was a place where travellers could whet their whistle, grab hot food, or catch a wink of sleep in a tiny room. Today, this National Historic Landmark (turned into an adobe building in the 1930s) functions as a museum with displays highlighting its own history, the once-nearby Route 66 road and the Civilian Conservation Corps too. 

San Diego's Balboa Park spans 1,200 acres and is packed full of photo ops. It's one of the oldest recreational parks in the United States, and home to several museums, gardens and attractions (including the zoo) plus chilled-out California vibes. Much like Central Park in New York, Balboa Park is a huge attraction itself and usually sees up to 15 million people flocking to hang out here every year.

Colorado Chautauqua Park was originally founded as the Colorado Chautauqua back in the 1920s. During this time in the US there was a movement for adult social and educational clubs, much like modern-day community centres called Chautauquas. The Colorado Chautauqua is now the only year-round example in the country and the longest continually-running one too. 

If you were wondering where the largest library in the world was, this is it. America's Library of Congress is the oldest federal cultural institution in the country. It's also the current research library for the US Senate and is where you'll find the US patent and trademark office. Both real-life and virtual tours of this amazing space are available.

Who knew that the start of Coca-Cola was in Atlanta, Georgia? Built in 1891, this facility served as the headquarters and bottling plant for the soda giant as it grew from soda shop to a mega-manufactured brand. However, as the company expanded, it outgrew the space. In 1966, Coca-Cola bid the two-storey Victorian property adieu and moved into something larger. Currently, it functions as part of Georgia State University's campus.

In the late 1800s, Honolulu's Iolani Palace was the official home of the Hawaiian monarchy. However, its life of royalty didn't last long as a coup saw the royal family overthrown in 1891. As the islands were transferred into a US state, Iolani Palace went from being a royal residence to functioning as a capitol building to, finally, disrepair. In 1978, after stunning renovations, the first two floors were opened to the public in all of their original grandeur. Discover more American castles you probably didn't know existed.

The United States' obsession with the stars didn't start by being the first country to land on the moon. We'd been ogling stars and outer space from afar long before then. Adler Planetarium, America's first planetarium popped up in Chicago back in 1930 and has been a dedicated research space ever since. It's also open to the public as a museum.

The annual Kentucky Derby horse race is about as American as apple pie. It's been running since 1875, but that's not what makes Churchill Downs, the actual horse track where the derby takes place, a National Historic Landmark. And no, it's not the fancy big hats, either. It's the main building's two iconic spires, built in 1895, which have become a symbol of Churchill Downs and the derby itself.

Located in Ganado, the Hubbell Trading Post (temporarily closed due to COVID-19) is the oldest continually operating trading post in the Navajo Nation and American Southwest. It's been a meeting place of indigenous and colonial settler culture since 1878, when Don Lorenzo Hubbell bought the small site to begin trade with the Navajo people who had recently returned from forced exile. 

The Battle of Bunker Hill took place in June 1775, during the siege of Boston and was an early fight for America's independence from the British. This one clash took the lives of over 1,000 British soldiers. Nearly 70 years later, a 220-foot (67m) obelisk monument made of pure granite was erected as a memorial. While it's remembered as the Battle of Bunker Hill, most of the fighting actually took place on Breed's Hill, closer to Boston.

In the 1920s, William Fox built a handful of large luxurious movie theatres around the country in places including Brooklyn, Atlanta, St. Louis, San Francisco and Detroit. The Detroit Fox Theater opened to the public in 1928 with opulent décor that reflected an East Asian theme and is currently the largest surviving movie palace from that time period. In 1988, the 5,000-plus-seat theatre underwent a complete restoration and is an architectural icon of the city.

One glance and it's easy to see why Split Rock Lighthouse is one of Minnesota's most photographed sites. However, Instagram-worthiness aside, this historic landmark has been a defining feature of Lake Superior's rocky North Shore cliff since 1910. This lovely lighthouse became a tourist attraction in the 1930s and today seasonal tours are available.

This isn't just any white clapboard home – you're looking at the house of a genius. Albert Einstein lived the last 20 years of his life in this two-storey Princeton home. However, unlike many residences of famous folks, at the request of Einstein himself, it was never turned into a museum. Since Einstein's passing it has been lived in by several notable scientists, including Nobel Prize winner and physicist Frank Wilczek. 

Around a mile north of Taos, New Mexico, you'll find one of the oldest continuously inhabited Pueblo communities in America. Taos Pueblo is remarkable for its multistorey, adobe-style buildings that date from the 13th and 14th centuries. This community remains home to indigenous Taos-speaking Puebloan peoples and is both a National Historic Landmark and designated UNESCO World Heritage Site.

In America, it's impossible to talk about the history of the LGBTQ struggle for rights without mentioning the Stonewall Inn in Greenwich Village. After starting its life as a nightclub for straight people, Stonewall was revamped into a gay bar back in 1966. It was here, fifty years ago, that the first Gay Pride took place a year. The Stonewall Inn is credited with sparking the gay rights movement across the United States and beyond, and still operates as a bar today. 

Did you know that Frank Lloyd Wright, probably America's most famous architect, has over 25 buildings on the list of National Historic Landmarks? Built between 1903-1905, Buffalo's Darwin D. Martin House is a masterpiece of the architect's Prairie style, showcasing low roofs and groups of windows, and is essentially a five-building complex including a pergola and carriage house. The museum also includes nearly 400 examples of Frank Lloyd Wright's glasswork, including his Tree of Life design. Private and self-guided tours are available. 

Another of Frank Lloyd Wright's most well-known works is the Mill Run property, Fallingwater, in the south of the Keystone state. FLW designed this stunner in 1935 for the Kaufmann family and it's an example of his groundbreaking approach to architecture which aimed to seamlessly integrate humans, nature and buildings. 

The Majestic may be now be moored outside of Manchester, Ohio but she has anchored herself in US history. Constructed in 1923, the Majestic was one of the last floating theatre venues ever built in the US and she kept the show afloat for an impressive 90 years. However, the show might go on thanks to a renovation project from the new owners. 

It may seem strange to have a sign on the list of historic landmarks, but the Northeast Entrance of Yellowstone National Park has a look so iconic it made the cut. The rustic, log cabin-like welcome sign for this gate has become synonymous with American national parks—and is a must-stop for pictures for the park's four-million-plus visitors every year.

Virginia's Natural Bridge is a 215-foot (65m) naturally-carved limestone gorge arch that looks like a bridge. And, it was once owned by Thomas Jefferson. Visitors can pay to check out the bridge from below in Natural Bridge State Park. But anyone looking to get a view from the top needs to hop in their car and head across on US Route 11, a highway which runs right next to the bridge.

While the Ames Monument may look like something from ancient Egypt, this four-sided, granite pyramid was actually constructed in 1881 by architect Henry Hobson Richardson. Located east of Laramie, it once marked the highest point on the Union Pacific Railroad, before the tracks were moved in 1901. The monument was erected to honour brothers Oliver and Oakes Ames, important leaders of the railroad's construction. The pyramid's base is 60-feet (18m) wide and it's 60-feet tall.

Old San Juan Historic District is the oldest settlement within Puerto Rico. An integral part of American Latino heritage, this colourful section of San Juan in the north of the capital features Gothic, Baroque and Renaissance architecture. In addition to being a district on the list of National Historic Landmarks, Old San Juan is also on the National Register of Historic Places and a designated UNESCO World Heritage Site too. 

These American landmarks aren't protected but they should be

Completed in 1883, Brooklyn Bridge is one of New York City's most famous sights and it has a rich history too. Given the bridge's lengthy span, New Yorkers were initially nervous about setting foot on the structure, and this fear was heightened after a stampede on the bridge killed 12 people. To help quell these anxieties, notorious circus man P. T. Barnum paraded 21 elephants across the length of the bridge to prove it was safe. Today, thousands of vehicles and pedestrians cross this East River bridge on a normal day and it's been a National Historic Landmark since 1964. 

This house in Hartford had a famous owner, the iconic American writer Mark Twain, aka Samuel Langhorne Clemons, who had it built in the late 1800s. The 11,500-square-foot (1,068 sqm) American High Gothic-style house was designed by architect Edward Tuckerman Potter and ended up being an expensive project wrought with delays. That didn't dampen Twain's creativity though, as while living here he wrote the classics The Adventures of Tom Sawyer and Adventures of Huckleberry Finn, among others. 

Discover more of America's most important landmarks