When most people think of wilderness, they think of mountains, forests, and other foreboding terrain. But just because a place lacks peaks and trees doesn't mean it's not wild. The Tallgrass Prairie National Preserve is a great example. Located in the Flint Hills, this 11,000 acre preserve represents some — most, actually — of the last of the 170 million acres of prairie that once covered our continent, affording a unique opportunity to see the American Heartland as it once was. Complete with buffalo. Tallgrass is home to one of the last remaining pure-bred bison herds, and you can even walk amongst them — if you're brave.