US Honeymoon recommendations- has anyone been to Nantucket, Martha’s Vineyard or Nashville?

We’re looking to do a U.S. honeymoon in July and we’re thinking maybe Nantucket, Martha’s Vineyard or Nashville. Has anyone ever been to these spots and would they be a good honeymoon location? We’re looking for a good even mix of relaxing and keeping busy. We’re open to other suggestions as well! Anywhere but California (we go there often to see family) or New York(where we live). Thanks!