Why a Wonder: Sand dunes are great to photograph, as is a nice serene sunset over the ocean. The fact that you can do both at Sandwich Harbor is wonderful.
Where: Sandwich Harbor in Namibia, is just south of the town Swakopmund. Access is restrivted, so a guided tour is the best way deep into the dunes.
When: Winter is best time to visit. I imagine that the other seasons are just too hot.