Prehistoric

See all the amazing life forms - from giant insects to giants mammoths - that have called Chicago home over the last 500 million years.

PREHISTORIC NEW YORK It's the ultimate city, packed with 8 million people and overgrown with skyscrapers. But before this land of glass steel and concrete sprouted, New York City was home to alien worlds and strange creatures stretching back over many millennia. Eight-ton elephant-like mastodons walked down what is today 5th Avenue, and a sea turtle bigger than a compact car swam directly over Midtown Manhattan. The Big Apple still bears the scars of a time when it was obliterated by a titanic glacier, and it sits on the site of a 200-million year old volcanic catastrophe. This is also where some of the world's first dinosaurs walked. And although it enjoys views of the Atlantic Ocean today, New York City was once in the middle of a vast desert continent. No matter the era, it's been the center of the action throughout the history of our planet.

From Triceratops and Tyrannosaurus to the nasty Terminator Pig and giant sea beasts, see what lived long before in prehistoric Denver.

PREHISTORIC DALLAS Reverse the clock over millions of years and we'll uncover the secrets of Dallas, Texas. From the ancestors of the famous Longhorn cattle that brought us the cowboys, to the mammoths, large cats and overgrown armadillos of the Ice Age, everything about Dallas was always BIG. Dive in to Ocean Dallas and swim with the Great White Sharks of the Cretaceous Period and the mosasaurs that battled them for dominance--right where downtown Dallas stands today. Then head west to Fort Worth and the home of the largest dinosaur to walk the earth in North America: Paluxysaurus -- the State Dinosaur of Texas. And if you think Texas is oil country, think again. At 325 million years old, it's the biggest natural gas field in North America -- and it's right beneath the city of Dallas.

PREHISTORIC WASHINGTON, DC The corridors of power run through its veins, a land of constant conflict and battles for supremacy. All of its history combines to tell the tale of why D.C. looks the way it does, and why it was built where it is. When the city was founded, was it really on a swamp? Before it was the nation's capital city, Washington D.C. was once a beach town whose waters were teeming with the largest shark the world has ever known. Dry-land was patrolled by a predator that looked like a dog, but was bigger than a grizzly. Tens of millions of years earlier it endured an asteroid impact that wiped out all life. Further back in time it hosted a ferocious meat-eating dinosaur that hunted building-sized plant-eaters ten times its own size, while directly over what is today the Washington Monument, flying reptiles with 30-foot wingspans terrorized the skies.

PREHISTORIC LOS ANGELES Where movie stars strut on the red carpet, bloody-fanged saber-tooth cats once stalked the grasslands. Where sun-worshipers bask on L.A. beaches, dinosaurs fought life and death battles. Los Angeles is the entertainment capital of the world, but in its distant past it was home of enormous Ice Age mammals, ravenous carnivorous dinosaurs and underwater sea monsters the size of a truck. The city emerged from the sea as gigantic tectonic plates clashed and gave birth to the earthquakes that still rock the city. Explore the history of the City of the Angels as it rewinds back in time... ten thousand years... fifty thousand years... 80 million years... to a mysterious and bloody past.