This steep-sided canyon was carved by the Colorado River in Arizona over millennia.
It is over 400 kilometres long and almost 2,000 kilometres deep. The canyon and its caves are full of Native American settlements. It is the only one of these seven natural wonders that have been inhabited for centuries. Where to see: Arizona, USA
When the winter season blankets the world in snow and transforms landscapes into glistening wonderlands, travel enthusiasts often seek out destinations that showcase the magic of this chilly time of year.