The White Nights are a phenomenon caused in St. Petersburg geographical location - at 59 degrees 57' North . St. Petersburg is the world's most northern city with a population over 1 million, and its stands at such a high latitude that the sun does not descend below the horizon enough for the sky to grow dark. In fact night becomes curiously indistinguishable from day, so much so that the authorities never need to turn the city's streetlights on.