Tourists flock to Walden Pond from across the globe

In 2024, Walden Pond was listed as an endangered place

The National Trust for Historic Preservation listed the site of Henry David Thoreau's "Walden" experiment as one of the most endangered historic places in America due to a proposed airport expansion and the proposed development of a nearby plot of land.

See the plot of land where Thoreau built his Walden cabin

Harvard's Lawrence Buell takes viewers down to Walden Pond to show them the spot in the woods where Thoreau constructed his modest cabin. Along the way, he reads from "Walden" and explains why Thoreau's text still matters 170 years after its publication.

Busting the myths about Thoreau's 'Walden'

This resource from The Walden Woods Project dispels some of the common myths about Thoreau's time in the woods, including that he was a hermit (he actually regularly visited friends), that he was freeloading (he paid off his debts), that "Walden" was a misrepresentation (he was forthcoming about editing his experiences), and that he was opposed to progress (he believed in practical technology).

How one professor uses 'Walden' to study climate change

Richard Primack, a biology professor at Boston University, uses observations on Walden Pond's ecology from Henry David Thoreau's book to inform his study of climate change, noting that "Walden" is one of the oldest datasets available in the United States.

Before writing 'Walden,' transcendentalist Henry David Thoreau nearly burned down his hometown with a campfire that grew out of control.

Read the books of Henry David Thoreau

Thoreau's books are all in the public domain, which means they're free from copyright—and free for you. Project Gutenberg has the landmark text "Walden," as well as lesser-known works such as "A Week on the Concord and Merrimack Rivers" and "The Maine Woods."

William HH Murray spurred American interest in rustic retreats

Murray's 1869 self-help book, "Adventures in the Wilderness; or, Camp-Life in the Adirondacks," encouraged urban residents to embrace outdoor activities, depicting upstate New York as an unsullied paradise free from the chaos of city life.

Take a tour of Mark Twain's Connecticut mansion

Twain and his family lived in a three-story, 25-room mansion in Hartford, Connecticut, from 1874 to 1891. Today, the home is a Twain museum, which includes several interesting artifacts, like his annotated books.

An estimated 40,000 Wampanoag populated 67 villages in the 1600s

For more than 10,000 years, native Wampanoag people have lived in and around Rhode Island and Massachusetts, especially in the islands known today as Martha's Vineyard and Nantucket. Roughly 5,000 dwell in the area today, after their numbers declined amid European migration.

Some vacationers flock to the sites of tragedies

Auschwitz, Chernobyl, Gettysburg, and more have all become tourist destinations, despite the horrible events that have occurred at the sites. The phenomenon is sometimes called "dark tourism," a trend that seems to be spurred by interest in history, morbid curiosity, and popular culture (like HBO's series "Chernobyl").

Mapping tourism at Machu Picchu

Only 750 people lived at Machu Picchu at its height, but today, almost ten times that number trample through its delicate plazas and agricultural terraces every day. This data visualization vividly illustrates the skyrocketing numbers of visitors to Machu Picchu over the decades, and highlights the risks of over tourism, including soil erosion and other environmental threats, and negative social and economic impacts.

Wisconsin left a deep impression on Frank Lloyd Wright and his work

Born and raised in Wisconsin, Frank Lloyd Wright openly adored his home state’s “pastoral” landscapes, red barns, and down-to-earth residents. Wright also referenced the state as a huge inspiration for his design style.

'The Wizarding World of Harry Potter' sparked record theme park attendance

A Forbes analysis found Universal’s parks in Florida, Japan, and California saw average attendance growth of 32% after opening Wizarding World attractions, with Orlando’s Islands of Adventure—the home of the Wizarding World—rising 64.5% to 9.8 million visitors.

National parks, explained

Roughly 83 million acres of the United States are set aside as federal National Parks land, an area large as Germany. From the original Yellowstone Park to small monuments and memorials, learn the essentials on this portion of America dedicated to public enjoyment and recreation with our quick explainer video.

'Vacation' wasn't common for Americans until the mid-1800s

Although we now consider vacation to be an integral part of the summer season, the concept didn't exist in the US until the middle of the 19th century. Even then, it was still a luxury and didn't become a middle-class norm until the early 20th century.

New England towns have practiced direct democracy since the 1700s

Town meetings in New England let residents vote directly on local budgets, laws, and policies. One of the oldest surviving forms of participatory democracy in the United States, the tradition dates back nearly 250 years.

Why Emily Dickinson's poetry remains popular in the 21st century

Dickinson remains widely read and is often considered one of American literature's greatest poets. This short documentary from PBS uses a 2017 museum exhibition on the writer to explore her long-lasting impact, with input from Barbara Howe, a contemporary poet, and Marta Werner, a Dickinson scholar.

Land use changes in Connecticut may have helped to enable Lyme's leap into humans

Forest clearing and fragmentation, alongside suburban development, may have contributed to the emergence of Lyme disease in humans in the 1970s. Those changes brought mice, carriers of the disease, into greater contact with people. Climate change is also facilitating Lyme's spread as tick populations survive milder winters and move northward.

See images of modern Druids who visit Stonehenge to celebrate the solstice

At the summer solstice, crowds at Stonehenge range from white-robed modern Druids with staffs and antler crowns to revelers with ox-horn trumpets or hula hoops—scenes regularly documented by photographers.

Boston opened the first subway tunnel in the US in 1897

By the end of the 19th century, nearly 400,000 people were packed into less than a square mile of downtown Boston, with 8,000 horses pulling trolleys through streets choked with noise, manure, and congestion. This prompted the city to pursue a then-controversial subway system.

Learn how aquifers and wells provide the largest reserves of accessible freshwater on Earth

Roughly a third of Earth's freshwater is stored underground in aquifers—permeable and porous rock formations where water naturally flows from the Earth's surface and accumulates. About half of this groundwater is accessed through wells, a feat of engineering used for thousands of years.

The controversy behind the Vietnam Veterans Memorial

It's now a standard stop for tourists visiting Washington, DC, but before it was built the Vietnam Veterans Memorial triggered an internecine battle between the war's veterans, some of whom believed the planned memorial was offensive. This short documentary recounts the controversy and the ultimate triumph of the memorial, which helped change the country's impression of the war and its soldiers.

Why one city in Minnesota isn't on Google Maps

North Oaks, Minnesota, is a city of a little over 5,000 people that spans just nine square miles. It's also the wealthiest place in the state, which is part of the reason it's been able to stay undocumented by Google. In this short documentary, one man attempts to film it himself.

Modern tennis was formalized in 1874

In the late 1800s England, a growing middle class could afford homes with lawns. With more lawns in England, Major Walter C. Wingfield saw an opportunity to bring lawn tennis to the masses. Modern tennis was formalized in 1874, when Queen Victoria granted a patent for Major Walter C. Wingfield's lawn tennis box set. The game was an instant hit, and by 1877, the new All England Club in Wimbledon began hosting a tournament.

Horace Mann was America’s champion of free, standardized public schooling

Horace Mann (1796–1859), Massachusetts Secretary of Education from 1837–1848, led the 19th-century Common School Movement. He established state boards, founded normal schools for teacher training, and urged universal, nonsectarian, tax-funded education. His reforms became national models.

The Erie Canal remains open to modern boaters

Nearly two centuries after its completion, the Erie Canal is still navigable. Each year, thousands of recreational vessels traverse its 339 miles of waterways—passing through historic towns, beautiful scenery, and restored locks.

Frank Lloyd Wright's houses are historically hard to sell because they're old, subject to local landmark commissions, and often unfashionable

The 19th-century painters of the Hudson River School were among the first American romantics, with portraits that displayed the natural beauty of the young country.

See how Budweiser's famous Clydesdales spend their days at Warm Springs Ranch, where roughly 70 to 80 of the beer brand's giant horses can be found at any given time.

Stanford built a Google Maps for the Roman Empire, revealing how much it cost to travel in the ancient world

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

The idea for the Federal Reserve was conceived in secret in 1910—with bankers donning duck hunt gear for disguise while traveling to a remote country club on Georgia's Jekyll Island

Explore an interactive map of battles from the American Revolution, along with detailed summaries of each engagement

Roughly 43 million US borrowers owe roughly $1.7T in student debt, the second-largest source of consumer debt behind mortgages.

The use of fungi to detoxify land and water—a process known as mycoremediation—has been used to clean up natural resources affected by the 2025 California wildfires.

See this overview of the firework rules across all 50 states, ranging from a complete ban on non-professional fireworks in Massachusetts to states with more lax rules like Indiana.

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

NBA superstar Victor Wembanyama spent the 2025 summer training with monks in central China to enhance his body and mind.

Poison ivy was sent to Europe in the 1600s as an exotic, ornamental oddity, where it was purposefully grown in the English royal gardens at Kew, the Faculty of Medicine in Paris, and a few other locations.

Explore the history, structure, and species of Australia's Great Barrier Reef with this interactive journey narrated by Sir David Attenborough.

Apollo astronauts left items in the moon's 'toss zone,' including golf balls, family photos, and bags of human waste, to make room for lunar rocks.

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

Waves off the coast of Nazaré, Portugal, can reach over 100 feet and are caused by the area's deep underwater canyon geography

The Mona Lisa's celebrity status and repeated restorations have obscured what made the painting so revolutionary for its time

Take a 3D tour of the Hajj, Islam's annual pilgrimage to Mecca, undertaken by more than 1.5 million Muslims each year.

A 2019 Facebook event called on attendees to "Storm Area 51, They Can't Stop All of Us," resulting in countless memes, the creation of a music festival, and eventually the arrests of those who did try to approach the area.

Warren Buffett's former professor Benjamin Graham is known as the 'father of value investing,' a strategy in which investors seek to buy stocks trading below their intrinsic worth.

In 2026, Finland was named the world's happiest country for the ninth consecutive year based on its wealth, social safety network, and high life expectancy, among other factors.

20,000 letters to the advice columnist 'Dear Abby' provide insight into prevailing sex, religion, and LGBTQ fears, anxieties, and concerns from the 1950s onward.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.