Countless folk tales have proclaimed that a region is protected from twisters by certain geographic features, such as a hill or river. The people of Topeka, Kansas, assumed they were being kept safe by a rise called Burnet Mound – that is, until the US city was ravaged by a killer twister on June 8,1966. If tornadoes can indeed go wherever they like, they appear to prefer some places more than others. America's Tornado Alley, stretching from north Texas to Minnesota, sees more action than any other place on the planet. Even on the local scale, variations can be dramatic. Dallas County, Texas, has seen about three times more tornadoes of note than adjacent Tarrant County, the home of Fort Worth. Just north of Geneva, Switzerland, lies a mini-Tornado Alley of sorts. A violent twister travelled some 60km/38 miles through the Jura Mountains from nearOyonnax, France, to Croy, Switzerland, on August 19,1890. History repeated itself on August 26,1971, when a tornado of similar strength covered a near-identical path. Destructive winds reported in the same valley in 1624,1768 and 1842 may also have been tornadic.