For life-list adventurers: Grand Canyon National Park, AZ

Paddling through the Grand Canyon is one of the great adventures you can have in your lifetime. The raft floats beneath towering rock walls apparently colored using the largest box of crayons in the universe. You trail your arm in the cool river, and the water is heaven. The current speeds up and your guide shouts, “Hold on!” because you’re approaching one of the rapids that would make the World River Rapids Hall of Fame if there were such a thing. The raft spins, buckles, cold water floods in on you, but amazingly the raft doesn’t flip over and you don’t fall out and you realize that every adventure you ever had in your life was just preparation for this one. Plus the fun continues beyond the river with some of the world's most epic hiking.

More: Grand Canyon National Park guide