Searching for lost history in an abandoned Appalachian frontier homestead.

Jay and his team search for treasures in an abandoned cotton gin.

Jay and the crew visit a 19th-century beer castle where they hope to find lost treasures of brewery baron Capt. Pabst.

An abandoned Gothic church is scheduled to be demolished.

The search for riches in an historic abandoned bank that was built to hold the fortunes of America's oil barons.

The historic Majestic Hotel in Hot Springs, Ark., was frequented for its luxury spas.

An abandoned paper factory the size of several football fields contains an assortment of historic items.

Marble from this factory was used in the building of the U.S. Supreme Court Building, the Tomb of the Unknown Soldier and the Jefferson Memorial.

Jay, Dan and Mark explore an entire abandoned village.

A trek through a spooky Masonic retirement home reveals a treasure trove of automotive relics.

The Old MacDonald farm includes a farmhouse, barn and mill that contain many historic items.

Historic treasures in a shuttered silk mill that's been abandoned since 1957.

The abandoned Scranton Lace Factory, founded in 1897, flourished for more than 100 years.

George Wyant and Tim Saylor get down and dirty in this series, which profiles the metal detector enthusiasts and homespun historians as they travel the country uncovering lost pieces of history. From bullets at historic battlegrounds to family heirloom rings and silver coins, the items -- "the juice" or "sweet nectar," as they call it -- often have little monetary value, but then again, Wyant and Saylor don't spend countless hours in a field or on a beach looking to strike it rich. It's the thrill of the hunt, they say, of not knowing what their next quest will unearth, that keeps them digging for more.

The old Dolly Parton hit "9 to 5" isn't a tune worth humming for the blue-collar pioneers featured in "Filthy Riches." The series spotlights ingenious Americans who skirt a conventional workplace in favor of making a living in the deep rivers, soggy mud flats and wild backwoods of the U.S. Ray Turner, for example, has been catching eels in Delaware for 30 years. He uses a self-made smokehouse in the woods to cook the critters and sell them. Billy Taylor and his sons hunt for prized ginseng root in the Appalachians. Taylor, a fully licensed wild ginseng dealer, promotes sustainability by planting its berries. In Maine, Jim Campbell and Andy Johns make the coastal mud flats their office, as they dig for valuable bloodworms to sell to fishermen. And Greg Dahl and Albert DeSilva are burl hunters. A burl is a hard, unwieldy outgrowth on a tree, usually at the trunk. Burls have value because of the spectacular patterns found in them when cut open.

When craftsman Jay Chaikin has a design idea, he relies on the environment for inspiration. In "Restoration Wild," Chaikin scours the countryside to reclaim abandoned items and transform them into livable, spectacular spaces, helping clients to reconnect with nature. His toolbox of materials includes rusted-out buses, old barns and abandoned railway cars -- weathered remnants of yesteryear that Jay and his team upcycle for the one-of-a-kind builds. The catch: the structures must flow seamlessly with the surroundings and appear to be a century old. With limited resources, Chaikin looks to the land to help deliver jaw-dropping results. In 2012, Chaikin was featured in the National Geographic Channel series "Abandoned," in which he and two buddies salvage valuables from dilapidated buildings.

Academy Award winner Morgan Freeman explores the meaning of life, God, and many big questions in between in an effort to understand how religion has evolved and shaped society. A different divine subject is covered in each hourlong episode, titles of which include "Creation," "The Devil Inside," "Afterlife," "Apocalypse," and "Who Is God?" To explore these topics, host and narrator Freeman visits nearly 20 cities in seven countries to see some of the world's greatest religious sites, among them Jerusalem's Wailing Wall, India's Bodhi Tree, Mayan temples in Guatemala, and the pyramids of Egypt, and he immerses himself in religious experiences and rituals. "In some places I found answers, and others led to more questions. The constant through it all is that we're all looking to be part of something bigger than us. If there's one thing I've learned, it's that we certainly are," Freeman says.

Maritime mysteries -- old and new -- come to life in this series, combining scientific data and digital re-creations to reveal shipwrecks, treasures, and sunken cities on the bottom of lakes, seas and oceans around the world. Innovative technology allows viewers to see what lies on the floors of large bodies of water such as the Gulf of Mexico, the Nile, the Indian Ocean, the Baltic Sea and the Atlantic Ocean as if they had been drained. Then, in a quest to explain natural wonders and man-made catastrophes, stories tell of how vessels sank, what ancient geological formations reveal about life on Earth, where Nazi secrets now reside, and why so many continue to search for the legendary city of Atlantis.

"It's the end of the world as we know it (and I feel fine)," sang R.E.M.'s Michael Stipe, and it's a proclamation that must resonate with the people profiled in this series. That's because they are all preparing for doomsday, whether it's caused by a natural disaster, a financial collapse or a nuclear winter, and their plan is to outlast and outlive any apocalyptic scenario. The series goes inside America's "prepping" subculture and introduces otherwise ordinary folks who are stockpiling food, water, weapons and whatever else they think is necessary in the event basic services should falter and society turns chaotic and violent. Also, each prepper's plan is reviewed by the consulting firm Practical Preppers, which analyzes its potential effectiveness in case the prepper's worst fears become reality.

The life of an Alaskan bush pilot is never dull.

Mick Dodge is one with the woods, having left modern conveniences behind 25 years ago to live among the trees, caves and animals in Washington state's Hoh Rain Forest. It's not an easy life by any means -- he sleeps in tree stumps and has no easy access to food -- but each day presents a different adventure, and as the always-barefoot Dodge says, "All I have to do is follow my feet." He's walking in the footsteps of four generations of Dodge men who have called the Olympic Peninsula their home, and because the intensely private former Marine allowed National Geographic access to his world, this time viewers are welcomed to witness the primal life of "The Forrest Gump of Middle Earth."

Each year adventurers make Alaska's mighty Yukon River their home for five weeks. They float downstream on homemade log rafts to sell firewood and other supplies to remote villages. The reality-documentary "Yukon River Run" presents hourlong episodes tracking the progress of various crews. As harsh winter months approach and threaten both safety and success, stakes are heightened as rafters endeavor to cash out and escape from the cold.

According to a legend that dates back to the 16th century, a cache of Incan gold worth hundreds of millions of dollars is hidden off the coast of southeastern Brazil. It's known as the "Treasure of the Trinity," and it's eluded all who have sought it for 500 years. But a modern-day team of explorers follows a radical new theory to uncover its whereabouts: a remote, treacherous island where thousands of deadly vipers roam. Cork Graham leads the expedition to Queimada Grande -- known to locals as Snake Island -- armed with advanced technology to unearth complex clues and decipher puzzles that have protected the treasure for centuries. This Discovery series takes viewers along on the epic journey to one of the most dangerous places on Earth.