Since 1872, when Yellowstone became America’s inaugural national park,these protected areas have enthralled visitors from around the globe. Currently the 63 national parks attract more than 300 million visitorseach year.But what is the X factor that draws people again and again tothese historic places or wilderness spaces?In thiscomprehensive guide readers will begin to understand the character ofthese parks, for each is, in its own way, truly unique.