MNN - Mother Nature Network

America's national parks are full of beauty and natural wonders, but they're also home to many things that can strike fear in the hearts of hesitant hikers: dark caverns, wild animals and complete isolation. For the most part, there's nothing to fear, but if you're looking to add a little spooky spice to your next outdoor adventure, check out these 10 parks. Local legends, historic hauntings and creepy creatures make these national parks the perfect places for Halloween hikes.