Ireland's Slane Castle has hosted over 1.5 million visitors for its rock concerts

On a cruise ship, the average person uses about 50 gallons of water a day, which is treated by bacteria and onboard filtration systems, then stored until the ship can legally discharge the wastewater.

The Berlin Wall physically separated East and West Berlin for nearly three decades, preventing East Germans from fleeing to the West and earning the nickname 'the Iron Curtain.'

Abraham Lincoln had to sneak into Washington, DC, in disguise for his 1861 inauguration after a detective uncovered a plot to assassinate him in Baltimore.

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

See a breakdown of how some of the most common food items are traded across the globe, including the key trade relationships for each item.

Use this tool to calculate the dollar value of your parental mental load, from meal planning to coordinating after-school care, then see resources that help generate solutions.

Humans may have as many as 100,000 to 150,000 individual hairs on our scalps, growing at a rate of roughly 1 centimeter per month.

Cats have a mutation that prevents them from tasting sweetness, and goldfish rank among the world's supertasters.

Explore (and debunk) the world's most contagious misconceptions—from the 5-second rule to sugar rushes—on this interactive site. Click on each misconception for further evidence.

Pregnancy makes someone more attractive to the mosquito species that transmits malaria.

Watch what would happen if you literally had all the money in the world.

'Tulip mania,' the 1630s Dutch craze where rare bulbs were briefly traded like luxury assets, may have been the first financial bubble—and it still shapes markets today.

Light takes approximately eight minutes to travel from the sun's surface to Earth, but it takes thousands of years to reach the star's surface from its core—a distance more than 200 times shorter.

Play the role of a student as you try to navigate college and remain debt-free.

The tallest tsunami in recorded history was 524 meters (1,720 feet) high—taller than the Empire State Building—and occurred in Lituya Bay, Alaska, in 1958 after an earthquake dislodged a rockface into the water.

Explore how temperatures compare to historical averages in cities worldwide with this interactive global monitor.

Watch 4-plus decades of Pixar's opening logos.

Explore a collection of famous literary maps, including original images from 'Treasure Island,' 'The Swiss Family Robinson, ' and 'Walden.'

'Golden blood' is the rarest blood type in the world—fewer than 50 people are known to have it.

The final shots of the Civil War were fired in the Arctic over 2 months after the South's surrender.

Explore an interactive forecast of the future of the universe, from the return of Halley's Comet to the last light in the cosmos.

Explore the wineries of Napa Valley with an interactive map of its hundreds of wineries, vineyards, and tasting rooms.

Plato's famous allegory of the cave is a metaphor exploring the value of truth over ignorance.

Visualize the path of every solar eclipse from 1900 to 2099 and see what each looks like when observed from different locations on Earth.

A dog's nose can be up to 100,000 times more sensitive than a human's, and each possesses a secondary organ for smelling, which helps learn about other dogs when they sniff each other's butts.

Between 2002 and 2012, at least 12 people were killed in the Philippines in incidents related to off-key karaoke singing of Frank Sinatra's 'My Way.'

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

The average banana produces one positron—the antimatter counterpart to an electron—every 75 minutes as its trace amounts of radioactive potassium decay.

Explore an interactive timeline of Earth's 4.5-billion-year history to visualize shifting landmasses and oceans, view the locations of significant asteroid impacts, and learn about major geological and biological events.

The animatronic shark from 'Jaws' was a complex machine called 'Bruce.'

If the moon were less than one-twelfth its current distance from Earth, the planet's tidal forces would overcome the moon's internal gravity, tearing it apart and forming a ring of debris.

The collapse of gas bubbles in the joint synovial fluid causes 'cracking' knuckles.

'Bibliotherapy' is of increasing interest as a way to improve mental health and help navigate complex life situations—with people immersing themselves in the experiences of fictional characters or nonfiction and self-help books to find relief and gain personal insights.

Apeirophobia is the fear of everlasting life and may stem from the human brain's inability to conceptualize the concept of anything happening beyond what it can project out, such as the concept of an infinite life.

In 1962, the US detonated a nuclear weapon in space, which produced an electromagnetic pulse that disabled three low Earth orbit satellites and damaged electrical equipment in Hawaii.

Lesser-known phobias include turophobia, or the fear of cheese, and nomophobia, the fear of being without your cell phone.

Explore 3D models of some of the most dangerous viruses, allowing us to understand these and other pathogens in new ways.

Computer scientists first started trying to optimize dating using computers in the 1950s.

Find out how important you are to AI tools when they generate text responses with this tool, which estimates the weights of people's names.

There are up to 100 trillion microbes in the gut, and maintaining the relative balance in this ecosystem is important for our health.