you do realize the grand canyon is *HUGE*, right? the south end of the park is where around 80% of people go, the north end accounts for the other 20%.
if you dont want to be surrounded by people, you dont have to be.
the beaches of north carolina are pretty sweet. we always go to sunset beach, which is small island off the coast of NC. it's usually pretty empty for a beach, but if you want to be by more people myrtle beach is only 30-45 minutes away.
oh yeah, when the tide goes down, you can swim to another island (bird island), which to my knowledge is pretty much uninhabited.