They're featured in Marhaba. Yes, it's a nice place, though prone to litter and, especially at weekends, guys racing in landcruisers. This also makes it a bit dodgy as a camp site.
They get their name from the fact that the sand makes a rather haunting, deep noise when you run or slide down them.
No facilities, so take water and shade. And take your litter home, please.
Final point. They'll seem easy to get to in daylight, but a lot trickier to get away from in the dark, if you're alone, or haven't been there before.