Interestingly enough, my dad and aunt owned some undivided interest in some "land" in coastal Louisiana. My Grandfather and his 3 siblings each owned a 1/4 share passed down from my great grandfather. There was a little mineral interest (gas wells), and they got a royalty check that usually didn't cover the taxes. When the lease expired, it wasn't renewed because they couldn't find anyone, or enough owners to sign a new lease. Several years ago, they drove over to Houma and talked to a lawyer that was able to get a map of the property, and it was about 90% under water at that point due to coastal erosion. They made the decision shortly after that (with agreement from my cousins and me) to stop paying taxes on it and let it go. The lawyer said Lafourche Parish had been trying to unwind that piece of property for years. Similar story in terms of newspaper ads, mailing tax bills to last known addresses, etc. Louisiana law is weird in that you technically still own the ground under water, but it's pretty much worthless unless someone can cure the title issues.