When the French colonized New Orleans in 1718, they encountered immediate problems. One was the high water table (about 12 inches), so burying bodies in the ground was not a good idea, so they built above ground cemeteries. Not uncommon in the tropical West Indies and what we call Central and South America.
Won't bore you with details. Here's a good article: https://en.wikipedia.org/wiki/Historic_Cemeteries_of_New_Orleans
We cherish our cemeteries. They are beautiful and we (and tourists) take thousands of photos of them.
That's all for now. Y'all stay safe.