How do I find the North Star?
Follow the two end stars of the Big Dipper's bowl about five times their distance.
Its height above the horizon equals your latitude: in Barcelona about 41° — roughly four fists up.
Because Earth's axis slowly wobbles over 26,000 years, the pole star changes: 5,000 years ago it was Thuban, in 13,000 years it will be Vega.