Remember the saying that lightning never strikes in the same place twice? Forget that. A remarkable site at the mouth of the River Catatumbo, branching off Maracaibo Lake in western Venezuela, is the stage for an amazing lightshow on average 150 nights a year, totalling a million flashes annually. Oddly though, no thunder follows the lightning. The bizarre phenomenon is found nowhere else on Earth, and is thought to be the single biggest generator of ozone on the planet.