They cooperate, make decisions, and even display a “primitive form of altruism,” scientists say.

In 1997, NOAA researchers recorded a mysterious ultra-low-frequency noise so powerful it registered on sensors thousands of miles apart.

People report anything from seeing colors to having near-death experiences. 

A mummified fossil fish was forgotten in a university basement until a son's chance discovery brought it back to science.

The eerie “sailing stones” in Death Valley National Park simply refuse to stay in one place.

A routine nature reserve project in the Netherlands turned up over 3,000 artifacts spanning thousands of years.

Although it killed more people, the Peshtigo Fire in Wisconsin was overshadowed by the Chicago Fire, which happened on the same day in 1871. 

You don’t need to visit the Grand Canyon to add whimsy to your life.

From 1876 to 1878, a strong El Niño wreaked havoc on the tropics. 

In 1934, a luxury cruise liner burned off the New Jersey coast. Ninety years later, no one can say for certain what—or who—started the fire.

Some experts think the cryptozoological legend is tied to an enigmatic owl. For others, the search is still on. 

Newly revealed documents show that, while breaking Nazi codes, Turing was also building a device that almost changed military communication forever.

This isn’t the fabled realm of Atlantis—but it’s almost as magical.

Beaked whales are famously private—even their mass grave was hiding.

Martin Couney, an American obstetrician, saved more than 6,000 babies. 

America's most futuristic luxury train hurtled into a Nevada canyon after someone pried the spikes out of a rail and shifted it four inches inward.

The stela where the date was carved depicts a ruler and a Jaguar god deity, showing how Maya kings used the Long Count calendar for power. 

For years, researchers assumed a 7,000-year-old mass grave pointed to a massacre, but the truth is far stranger.

Because the seal had never been broken, the Etruscan tomb’s grave goods had also gone completely untouched by looters.