Yes absolutely! Hilton Head is over 30% seniors (http://www.eretirements.com/best-places-to-retire/south-carolina/hilton-head)
I would also recommend Myrtle Beach, Beaufort, and Brevard, all of which have a population with at least 15% seniors. Check out more information on them below:
We will be posting some other cities in the coming weeks that may meet your criteria, including: Asheville, Pinehurst, and New Bern. Be sure to check back soon!