Tuonela is the realm of the dead or the Underworld in Finnish mythology, similar to Hades in Greek mythology. Tuonela, Tuoni, Manala and Mana are often used synonymously. In Estonian mythology, it is called Toonela or Manala.
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 (similar to Charon), 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. After his return he curses anyone trying to enter the place alive.
Tuonela is used as the translation for the Greek word ᾍδης (Hades) in Finnish translations of the Bible. In Christianity it is often interpreted as the resting place of the dead before the Last Judgement.