Watch Full Seasons on 
Shows

Get Ready to Go Ballistic with Dodgeball Thunderdome

Photos from the Edge

One Man's Expedition to the Edge

See Rare Archival WWII Photos from Apocalypse '45

Apocalypse '45 Poster Gallery

Apocalypse ‘45 Asks How We Remember WWII

Lupita Nyong'o Takes us Back to Serengeti

Captain Johnny Johnson Jr.'s Secret Sauce

Why We Hate Returns to Explore The Reckoning

Tell Us About Your Hobbies and We'll Tell You Which Diesel Brother You Are!
See All Shows
DNews

Shipwreck Causes Environmental Crisis in Indian Ocean

Save the Sea Animals

Are Shark Attacks on the Rise? Not Really.

Pangolins, World's Most Trafficked Animal, May Finally Be Safe

Fur Family Tips from Cat Daddy Jackson Galaxy

Zoo Miami Tests Gorilla for COVID

You've Gotta be Kitten Me

Baby Raptor Fossil Found in Alaska

There’s a Lot You Don’t Know About Sharks

Locust Swarms Plague India
See All DNews
Nature

Shipwreck Causes Environmental Crisis in Indian Ocean

This is What is Killing Sharks

#TBT: Sharks in Cuba

The Underwater Shark Photography of Amos Nachoum

The Jaws Boat is Being Rebuilt, But This Time to Save Sharks

Save the Sea Animals

The Majestic Chisos Mountains

The Beauty of Big Bend National Park

Are Shark Attacks on the Rise? Not Really.

Cat's Out of the Bag - International Tiger Day is July 29th
See All Nature
Exploration

Zen and the Art of Shark Diving

The World's 7 Scariest Drives

7 Places for the World's Best Stargazing

Tour Paris by Photograph

5 Wonders You Probably Didn't Know Were Man-Made

Aztec Secrets Unearthed in New Science Channel Special

Female Ocean Rower Attempts Record-Breaking Solo Crossing

Why the People of Myanmar are Fighting Conservation Groups

Dr. Kathy Sullivan is an Explorer of Firsts

Exploring Isolation: Inside the Minds of Legendary Explorers
See All Exploration
Space

Waste In Space: NASA's Lunar Loo Challenge

Looking Down: NASA Astronauts Share Images from Space

Welcome Home Bob and Doug: SpaceX Crew Dragon Splashdown Complete

Congrats NASA and SpaceX! Here's a Recap of the Splashdown to Earth

SpaceX Crew Dragon Undocked and Ready to Return

What to Know About the Splashdown to Earth

NASA's Perseverance Rover is on its Way to Mars!

Will a Colony on Mars Ever Be Feasible?

10 Facts About NASA’s SpaceX Demo-2 Splashdown

One Night, Two Meteor Showers - Tonight!
See All Space
Science

Hurricane Prediction: The Forecasting Science that Saves Lives

Spider Silk: Wonder Material Used to Heal the Human Body

The 2020 Planetary Primaries

See Comet NEOWISE Before it Disappears

The Moon Event: Happy National Moon Day

Red Rover, Red Rover, Send Perseverance Right Over

Too Big to be a Neutron Star, Too Small to be a Black Hole. What Am I?

Clean Air Tech and Pollution Reduction Post-COVID

Something Funky is Happening to the Earth’s Magnetic Field

Emotional Robots: Machines that Recognize Human Feelings
See All Science
Motor

Hydrogen Power: Moving the World into Clean Energy

Tune-Up Your Engines, American Chopper Returns August 4th

Most Remarkable Cars from Motor Monday

Safety Updates for Classic Cars

Jesse James Returns to Discovery in an All New Season of Monster Garage

Mods for Beginners

Carroll Shelby: The Man Who Raced Against Ferrari with a Ford

Classic Chevys

Gifts for Car Lovers

Cool Convertibles We're Crushing On Right Now
See All Motor
Schedule
More
Cancel
Season 4, Episode 3

Wonders of the Underworld

New discoveries reveal various deserted, underworld engineering projects -- from a terrifying sea fortress to a strange complex of towers in a forest of ice. Experts explain why they were built and why they were eventually abandoned.
See Tune-In Times

Previous Episode

Curse of the Castle

Next Episode

Left Behind