what is the largest sand dunes?

Answer 1

They think the largest sand dune is "Big Daddy" located in Africa in the Namib Desert. It is one of the oldest sand dunes and rises 1,200 feet.

Here is some information and a photograph of it. Also there are some remarkable photos if you type in Big Daddy +sand dunes and click images.

http://americandigest.org/mt-archives/004231.php

Answer 2

The Imperial Sand Dunes also called the Algodones Dunes is the largest mass of sand dunes in California.

Answer 3

In southern Africa, the Namibian Sand Dunes are the tallest sand dunes in the world, about 200 meters (650 feet) high.