Barringer Crater, Ariz.
© Charles O'Rear/CORBIS
Thanks to the work of conservationists and the National Parks Service, the dramatic landscapes of all the top wonders have been preserved, along with the lesser-known national treasures, like the remarkable spires of Fisher Towers or the subterranean marvels of the Lost Sea. Whether its a top wonder or a hidden gem, its worth remembering the words of Teddy Roosevelt, who looked with wonder across the Grand Canyon and remarked, Keep it for your children, and your childrens children, and all who come after you.
Buried beneath the bedrock of central Kentucky is Mammoth Cave National Park, the longest cave system in the world. Sprawling across more than 50,000 acres, the World Heritage Site and Biosphere Reserve offers splendid spelunking. With 365 miles of known passageways, it dwarfs the competition: South Dakotas Jewel Cave, the worlds second-longest cave system, boasts just 145 miles of passages.
The native Athabascans called it Denali, or the high one an apt name for North Americas tallest peak. Soaring 20,320 feet above sea level, Mt. McKinley crowns one of Americas wildest frontiers in Alaskas Denali National Park. The first climbers conquered the mountain nearly a century ago; today nearly half those who attempt the ascent make it to the topthough close to 100 lives have been claimed by the mountain through the years.
High above the rose-red landscape of southern Utah, these remarkable rock formations rise like sandstone sentries guarding one of the countrys most magnificent regions. Centuries of wind and rain have shaped the Fisher Towers; today the abstract, sculpted towers and spires attract legions of climbers. The ascent of the famous corkscrew summit isnt for the faint-hearted: Its a long 500-plus feet from the top to terra firma.
The Lost Sea
Buried deep beneath the surface in Sweetwater, Tenn., the Lost Sea is the largest underground lake in the U.S and second-biggest in the world. Part of Craighead Caverns, it was discovered more than a century ago by a 13-year-old exploring the sprawling cave system. The caverns are filled with crystal clusters, stalagmites, stalactites, eerie rock formations and even an underground waterfall.
Two Ocean Pass
Straddling the Continental Divide, this mountain pass in Wyoming offers a unique aquatic phenomenon: a stream which breaks off into two tributaries, one flowing west toward the Pacific Ocean, the other flowing east toward the Gulf of Mexico, and, ultimately, the Atlantic Ocean. A fish could theoretically swim across the whole breadth of the continent via the pass the only one of its kind in the United States.
Its believed that this massive crater in the Arizona desert some 4,000 feet across, and nearly 600 feet deep was formed by a meteor impact 50,000 years ago. Scientists estimate the hunk of cosmic rock was traveling close to 30,000 mph when it hit the earths surface. Barringer Crater was named for the engineer who was the first to suggest, in 1903, it was caused by a meteorite; three years later, President Theodore Roosevelt authorized the establishment of a post office nearby at Meteor, Ariz.
City of Rocks
The only city in Idaho without a single soul to inhabit it, this collection of granite monoliths and soaring pinnacles includes rock formations more than 2.5 billion years old. Today the City of Rocks is a favorite for climbers, but it was wagon trains of California-bound settlers who left their mark in the 1840s. They scrawled their signatures on the rocks with axle grease, many of which are still visible today.