More than 200 years ago, a scientist named Alexander von Humboldt embarked on a perilous five-year journey through the Venezuelan jungles and Andean Mountains of South America. At the time, it was believed that the world was less than 6,000 years old. Humboldt's groundbreaking observations and theories would not only inspire Charles Darwin, but change our understanding of nature–and the role human’s plays in it–forever. Follow historian and best-selling author Andrea Wulf as she recounts his footsteps and discoveries.

Few places on Earth remain largely untouched and uninhabited by humans, but such spots exist in the middle of the Atlantic Ocean. Welcome to the Mid-Atlantic Ridge, a vast chain of volcanic mountains that have surfaced as tiny, isolated islands thousands of miles from any mainland. These worlds serve as both playgrounds and sanctuaries, where some species struggle and others thrive. Discover the secrets of these little-known oases as we explore eight islands, from the Arctic to the Antarctic.

In 2018, two volcanoes unleashed terror on their communities, but in very different ways. Fuego, the Volcano of Fire in Guatemala, sent boiling clouds of gas, ash, and rock down the volcano's slopes and into villages, killing hundreds. In Hawaii, Kilauea spewed out over four billion cubic feet of lava, razing estates, destroying roads, and changing the landscape. Using the latest scientific evidence, we explore what made the eruptions unique, why they were so hard to predict, and whether or not these two catastrophes were somehow connected.

At the Nyaru Menteng Orangutan Rescue & Rehabilitation Center, the challenges come often and fast, from teaching the orphaned orangutans essential life skills to ensuring the more rambunctious members of the class don't cause too much mayhem. There are fruit kebabs as treats, baby orangutans in diapers, and many other delightful moments. But the future these orphans face is far from certain, as they work to overcome traumatic pasts, learn the skills they need to survive, and progress towards a carefully planned release back into the wild.

It's the deadliest tsunami on record, causing 230,000 deaths and $15 billion in damages. Triggered by a massive undersea quake off the coast of Indonesia, the 2004 Asian tsunami pounded Indian Ocean coastlines with waves up to 100 feet high, catching victims and the world's leading scientists by storm. Are we better prepared for the next big one? Where will the next one hit? See how early warning systems are currently being developed and meet the lucky few who survived this epic disaster.

The legacy of Prohibition is one of failure. Instead of making a more sober America, it weakened the nation's respect for the rule of law, enabled the expansion of organized crime, and turned city streets into battlefields. But it was also an era of great consequence, prompting federal criminal law enforcement and the expansion of the U.S. prison system. Revisit this defining moment in American history to see how it shaped the course of the 20th century and how its impact still reverberates to this day.

Weather balloons. Atmospheric phenomena. Experimental military aircraft. There are explanations for most unknown flying objects, but not all of them. So, are flying saucers real? Many Americans believe extraterrestrial visits are possible, and in 1952, the U.S. Air Force even launched Project Blue Book, history's most extensive government investigation into UFOs. Join us as we pour over recently declassified reports, meet with science experts, and hear eyewitness accounts to see if we are indeed sharing our friendly skies.

Few creatures have revealed as many biological secrets about the workings of life on Earth as the backyard lizard known as the anole. Join biologists Neil Losin and Nate Dappen on their yearlong examination of this humble but fascinating creature and its remarkable powers of adaptation. It's a whirlwind journey that takes us from Caribbean rainforests to high-tech labs to the city of Miami, leading to incredible discoveries about the laws of the lizard.

Journey to the Luangwa Valley, a pristine wilderness that’s home to a magnificent array of animals. Here, predators and prey alike have developed ingenious adaptations to help them overcome blistering droughts and torrential rains. Observe iconic African wildlife like lions and leopards, herds of elephants, massive crocodiles, and tussling giraffes, as well as unsung heroes like hyenas, baboons, bats, and beetles. In this land of extremes, every creature plays a pivotal role in the daily fight for survival.

American-born Julie Montagu, Viscountess Hinchingbrooke, visits great estates in the United Kingdom.

From the locomotive to rail traffic control to the maintenance depot, Mighty Trains takes audiences on a journey riding the rails around the world. We will follow the engineers and conductors as they navigate their way through busy rail yards, vie for priority departures and deal with the unexpected, oftentimes on railways designed almost 200 years ago.

With their distinctive appearance, trademark bounce, and babies in pouches, kangaroos are Australia's most iconic marsupial. But kangaroo life isn't without its challenges: Predators like the dingo or goanna are always looking for dinner, and evading them is life's number one priority. Take a closer look at the up-and-down life of an Australian icon.

Over the course of nearly half a billion years, which deadly predator ranks as the biggest and baddest? Join us as we travel through time and across the world to present this terrifying top ten ranking. We uncover new evidence, put theories to the test, and feature icons like the Tyrannosaurus rex and the saber-toothed cat, plus lesser-known beasts like the terror bird and the giant lizard Megalania.

Can the length of our fingers predict our sexual preference? Do our genes make us commit adultery? Should breast milk come with a warning label? Thanks to modern medicine and science, we're not just finding out new answers about the human body and condition, we're coming up with brand new questions. Join us as we reopen provocative, and sometimes scandalous, subjects once considered closed. We'll separate medicine from myth and science from snake oil to reveal new truths about who we are, what we're made of, and where we may be headed.