Sand Dunes that Croak, Whistle, Boom and Sing

When early humans heard these strange sounds in the middle of the desert they attributed them to many supernatural origins. Marco Polo believed they were spirit voices, and likened the noises to "the sounds of all kinds of musical instruments," and also "of drums and the clash of arms."
Find out how the different noises are made, and even listen to them yourself.

Individual grains of loose surface sand bounce up and down over the compacted lower layers of the dune. The interaction between the upper- and lower-layer sand grains produces vibrations that make sound, much as a violin string does as a bow passes over it.

The sound has been compared to the low note of the didgeridoo or a low-flying plane.

Link – via atlasobscura

From the Upcoming ueue, submitted by coconutnut.