I remember the Wind Cave system in the Black Hills of South Dakota, sacred to the Lakota Sioux people and close to the American dark-matter detection laboratory set deep in the worked-out gold mine. From the opening to Wind Cave, which extends for more than 130 miles below ground, air rushes or is drawn with such force that it can strip hats from heads. In the Lakota creation stories it is from Wind Cave that humans first emerge into the upper world, where they are astonished by colour and space.
