This beautiful mushroom’s colors are a sign to stay away. It produces a poison that will sicken people unless it is cooked very thoroughly.

In most uses, this word refers to something that can harm or kill an organism. But in biology, only some organisms that make a toxic substance are considered truly poisonous. To get that name, they must secrete the chemical passively. Then it just stays on or inside the organism until somebody — or something — eats it. Plants can be poisonous. So can animals that secrete toxins through their skin. But if an animal has to bite or sting to deliver its toxic chemical, scientists call it something different: venomous.

Feel weightlessness for a few brief seconds by jumping off a cliff into refreshing water below. This extreme feat was once a test of bravery for Maui's King Kahekili II, who would make his warriors jump off a cliff into the water to prove they were loyal and fearless.

Taos, New Mexico — which has been drawing artists to its ancient surroundings since the very end of the 19th century — is a magical place well worth a visit in its own right. The Taos Pueblo, a five-story series of adjoining homes, dates back a millenia and is one of the oldest continually inhabited communities in America.

Any trip to Mexico City should include a visit to this fascinating Mesoamerican city just 30 miles northeast of the capital. The pyramids and other structures here date to 400 BCE; by the time the Aztecs found the city in the 1400s, it had already been abandoned for centuries. They named it “the place where the gods were created,” or Teotihuacan.

The giant blocks of stone called the Trilithon that make up the base of this Roman temple in Baalbek, Lebanon remain a great mystery of the ancient world despite over 100 years of study by archaeologists.

The 1930s discovery of thousands of megalithic stone jars dotting a remote landscape in Laos has long intrigued travelers and scientists alike.

There’s a curious little forest in far-western Poland near the German border where trees grow at a 90-degree angle at their base — and no one knows why. This mystery is doubly intriguing because the Crooked Forest, as it’s known, is surrounded by a non-crooked forest of trees that grow straight up in the normal way.

Deep in the northern deserts of Mexico is a 30-odd square-mile area where things are just a bit off. In the earthly realm, the Zone contains dozens of flora and fauna endemic to the area and is rich in uranium and magnetite. It’s the otherworldly claims, however, that are most intriguing.

Few if any presumed UFO sites are as rich with conspiracy as the one formerly owned by billionaire Robert Bigelow in the Utah wilderness 150 miles east of Salt Lake City. It helps that a movie in the found-footage genre called “Skinwalker Ranch” was filmed there in 2013, and that the ranch was featured in the “Extraordinary Beliefs” documentary series. Add that to decades of mysterious sightings and encounters, and you have (allegedly) a full-fledged government cover-up in plain sight.

Whether you believe in extraterrestrials or paranormal activity, there’s no denying the bizarre at Skinwalker Ranch, where there have been reported sightings of UFOs, bigfoot-type creatures, animal mutilations, unexplained lights, poltergeist activity and crop circles. These things have been reported throughout Uintah County, but are in the highest concentration around the ranch.

The ranch was named after the Navajo legend about harmful witches who disguise themselves as, turn into or possess any animal.

Across the Mississippi River from St. Louis there once was a thriving city of 20,000 American Indians from many different cultures — making it at the time the largest and most sophisticated city in North America outside Mexico, with a larger population than European cities like London.