Tuonela is the realm of the dead or the Underworld in Finnish mythology. Tuonela, Tuoni, Manala and Mana are used synonymously. In Estonian mythology, it is called Toonela or Manala.
According to the ancient beliefs the fate of good and bad people is the same and the dead wander the afterlife as shadow-like ghosts. Tuoni and his wife Tuonetar are the rulers of Tuonela. At times living people visited Tuonela to gather information and spells. The trip there required weeks of trekking in a desert, and finally the crossing of the river with the help of a ferryman (similar to Charon in Greek mythology). Shamans could visit Tuonela by falling into a trance and tricking the guards.
Tuonela is best known for its appearance in the Finnish national epic Kalevala. In the 16th song of Kalevala, Väinämöinen, a shamanistic hero, travels to Tuonela to seek the knowledge of the dead. On the journey he meets the ferryman, a girl, Tuonen tytti, or Tuonen piika (Death's maid), who takes him over the river of Tuoni. On the isle of Tuoni, however, he is not given the spells he was looking for and he barely manages to escape the place by turning into a snake. After his return he curses anyone trying to enter the place alive.