Which desert's 'singing dunes' span Namibia's coast?

The Namib, which also has the strongest claim to being the oldest desert on Earth - arid for something like 55 million years, long enough for a genuinely bizarre set of specialists to evolve there.

The singing is real and was explained only recently. Large dunes emit a deep hum, sometimes over 100 decibels and audible for kilometres, when sand avalanches down a slip face - the grains synchronise into a coherent vibration, and the frequency depends on grain size, so different dunes sing different notes. Marco Polo heard it and attributed it to spirits.

The fog is what keeps the place alive. Cold Atlantic water produces a fog that rolls inland most mornings, and the animals harvest it: a darkling beetle climbs a dune at dawn, does a headstand, and drinks the water that condenses on its own back and runs to its mouth. The Welwitschia plant, which grows two leaves and nothing else and can live over a thousand years, does something similar. The coast where the fog forms is the Skeleton Coast, named for the shipwrecks and whale bones along it.