põhjanael, in Estonian folklore, the North Star. Before the influence of Christianity, Finnic peoples shared a worldview in which the firmament was supported by a gigantic pillar, tree, or mountain, around the top of which the sky turned. Estonians visualized the sky as an upturned cauldron to whose bottom a nail had been affixed, allowing the sky to turn on it as on an axis. The nail, called the põhjanael, was identified with the North Star.