This is Little Sahara, a 2 square kilometer set of sand dunes in the southern central portion of Kangaroo Island, Australia.  You can sandboard, sand ski, sand sled, etc there.  There is a fairly tiring climb to get to the top of the dunes as every step you sink into the sand, but then you can fly down on the sand’s surface on whatever device you choose.  You can bring your own equipment or rent there (but it’s pretty expensive).  But if you are looking for a unique experience (which I strongly recommend you do when you travel, for happiness sake), this is one.

Happy travels!