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.

Travel the 363-mile Erie Canal, the waterway that cut freight costs by 90% and opened the American frontier.

The space race was a Cold War rivalry between the US and the Soviet Union that culminated in the US landing astronauts on the moon in 1969.

The Middle Ages, the roughly 1,000-year period between the fall of Rome and the Renaissance, shaped the political and cultural foundations of modern Europe.

The Maya were an ancient Mesoamerican civilization that built dozens of major cities across present-day Mexico and Central America.

Machu Picchu is an ancient Incan citadel set high in the Andes Mountains in Peru, abandoned for centuries before its rediscovery in 1911.

The Wampanoag Nation inhabited the northeastern coast of North America for 12,000 years before European contact killed an estimated two-thirds of their population in a single generation.

When Mount Vesuvius erupted in 79 CE, it buried the Roman city of Pompeii under 20 feet of ash, which preserved it for nearly 1,700 years.

The Aztec Empire ruled over 80,000 square miles of central Mexico for nearly a century—until a small band of Spanish conquistadors brought it down in 1521.

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.

Meet the Night Witches, the all-female Soviet bombing unit so feared by the Nazis that shooting one down earned a soldier one of the highest military honors.

The connection between druids and Stonehenge stems from a historical misconception.

Stonehenge was built using giant wooden rollers and precisely carved tongue-and-groove joints to lock the stones in place.

Stonehenge is one of the world's most studied prehistoric sites and was built around the same time as the Great Pyramid of Egypt.

Take a virtual tour inside Stonehenge.

Before humans, the Soviet Union and the United States sent animals—including apes, dogs, and cats—to space during the Space Race.

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

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

Explore the archaeological treasures of Pompeii, the city buried under volcanic ash when Mount Vesuvius erupted in 79 CE.

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.

US intelligence allegedly pursued more than 600 schemes to assassinate Cuban revolutionary Fidel Castro.

Iran's Revolutionary Guard Corps is independent of Iran's regular army and is one of the most powerful and influential military-political organizations in the Middle East.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.