S. S. Atlantus (better known as the concrete ship).
Note: You can click on the photo in this post to enlarge it to see the details, which I highly suggest you do so that you can see what remains of this ship!
You can read all about the history of the S. S. Atlantus which was one of the original concrete ships and was in the World War I Emergency Fleet. Since it's sinking (from a storm) it has become a major tourist attraction down in Cape May, New Jersey.
You can stand right on Sunset Beach and see what remains of the sunken concrete ship which is really cool to see. Personally, I think it's best to view it early in the morning or later in the evening as a lot of fisherman like to fish off Sunset Beach and some of them can be rude when tourists are around trying to see the Concrete Ship.
If you are hungry you can grab a bite to eat at the Sunset Beach Grill (a few yards away), take in some shopping (3 stores are on the beach) or take in a round of miniature golf. All are within walking distance.
The World War II Lookout Tower, All Veterans Memorial and the Cape May Lighthouse are all close by too! This makes for a great afternoon with the family so if you are heading to Cape May this summer, make sure you check out all of these wonderful tourist attractions too!