Explore the full list of over 1,000 UNESCO World Heritage sites, broken down by country.

Cartoonist Thomas Nast helped bring down Boss Tweed, one of America's most corrupt political bosses.

John D. Rockefeller—the world's first billionaire—was born to a well-known con artist father.

With the help of one photographer who took photos of children at work, child labor in the US was eventually restricted by law in the mid-1900s.

Near the end of the 1700s, the United States was forced to pay Barbary pirates an annual tribute equal to 16% of its entire budget.

In 1822, French scholar Jean-François Champollion deciphered Egyptian hieroglyphs using the Rosetta Stone.

Explore the major archaeological sites of Egypt's 3,000-year history.

During the Cold War, a mid-air fire led to a nuclear bomber crash in Greenland that left a piece of a hydrogen bomb missing to this day.

The Lewis and Clark Expedition unexpectedly ran into Sacagawea's long-lost family in the Rocky Mountains.

The Lewis and Clark expedition purchased more than 260 separate items to supply their journey, including 120 gallons of whiskey.

Sacagawea's son, Jean Baptiste, who was born during the Lewis and Clark expedition, traveled to Europe as a duke's companion before returning to the American West.

Lewis and Clark identified 122 animal species new to science.

William Clark negotiated one-tenth of all ratified treaties between Native Americans and the US.

Explore Lewis and Clark's 8,000-mile journey in Google Earth.

The prophetic Oracle of Delphi was believed to have a direct line to the Greek god Apollo.

The prophetic Oracle of Delphi held real power in ancient Greece.

Visit the Acropolis of Athens, the fortifie high city that hosts the iconic Parthenon temple, with travel writer Rick Steves.

The Greek city of Alexandria in Egypt helped form the template for modern cities by considering function, commerce, culture, and politics.

Watch the many different civilizations around the Mediterranean shift power from the year 2500 BCE to 0 BCE in this animated map.

See artifacts from the ancient Olympics at the Met.

Socrates, who never wrote down his ideas, is considered by many the father of Western philosophy.

Meet the scientists who worked on the Manhattan Project.

Worried that Nazi Germany could weaponize nuclear fission first, Albert Einstein wrote a 1939 letter warning President Roosevelt about the possibility of atomic bombs—a decision he later regretted.

The Manhattan Project operated at three key sites, each with a distinct role in building the first atomic bomb.

The Manhattan Project, the top-secret American program that built the world's first atomic bomb, cost $27B in today's dollars and reshaped global power.

Plato's famous allegory of the cave is a metaphor for the value of learning the truth.

The Greeks weightlifted using massive stones and admired strength—but viewed muscles differently.

An analysis of ancient texts found that dementia was rare in ancient Greece.

Watch a quick overview the rich heritage of the ancient Greeks.

The Greeks named their dogs with short names similar to modern ones.

Hear what ancient Greek music sounded like.

Explore different ways the ancient Greeks laid the foundation of Western culture, from philosophy to sports (w/quiz).

Raphael's Renaissance masterpiece 'The School of Athens' visually contrasts the views of philosophers Plato and Aristotle.

Since World War II, US and Soviet/Russian leaders have repeatedly agreed to arms control treaties, though strained tensions have led to the expiration of agreements in recent years.

Explore 100 years of communism across the globe, from the 1917 October Revolution to North Korea's modern nuclear defiance.

Estimate the costs of taking a vacation in ancient Rome.

Ancient Greek astronomer Hipparchus created accurate maps of the night sky way ahead of his time, with coordinates sometimes within a single degree of modern values.

Watch a day in the life of a fictional Athenian family during the Peloponnesian War, ancient Greece's worst internal conflict.

Ancient Greece originated roughly 4,000 years ago around the Aegean Sea, and over centuries expanded as far as Spain and India.

The formal Japanese unconditional surrender that ended World War II took place on the deck of the USS Missouri in Tokyo Bay on Sept. 2, 1945.

Because the Korean War ended with an armistice rather than a peace treaty, North and South Korea are technically still at war.

Watch the 1986 Challenger disaster, which killed all seven astronauts aboard, unfold live.

Beyond technical failures, the 1986 Challenger disaster exposed deep flaws in NASA's leadership.

The Middle Ages produced inventions that still affect our lives today, like coffee houses and improved agricultural techniques.

Explore a map of Medieval Europe, which was a patchwork of hundreds of competing states.

Watch the Panama Canal's lock system lift a ship 85 feet above sea level to cross between two oceans.

Working conditions on the Panama Canal, built between 1904 and 1914, were abysmal, with thousands of workers dying on the job.

The Wright Flyer was an engineering breakthrough, and modern aircraft still use the same principles of flight.

Before their historic flight, the Wright brothers ran a bicycle shop in Dayton, Ohio, where they built the world's first successful powered aircraft.

A bankrupt flour merchant in debtor's prison helped inspire the Erie Canal.