This is the purported tomb of Marie Laveau in the Saint Louis Cemetery Number One in New Orleans. Visitors ask Marie for a favor then leave their mark and small offerings to the queen for good luck.
Apparently some people don't believe that the Voodoo Queen is in the first tomb pictured, as you can find red XXX's at several more locations in the cemetery. I don't know which one is real, but I left a penny at each one just for good luck. This is one damn creepy place, and they lock the gate promptly at 3 PM.
One interesting fact, the cemetery used to be a lot larger. The graves were moved to make way for the big housing project next door. Haunted housing !