Tuonela is a concept from Finnish mythology that represents the realm of the dead. It is often depicted as a dark, misty place where souls go after death. In this underworld, the spirits of the deceased reside, and it is ruled by the goddess Tuoni and her consort, Tuonetar. In Finnish folklore, Tuonela is not a place of punishment but rather a tranquil resting place. The river Päijänne is said to flow through Tuonela, separating the living from the dead. The journey to Tuonela is often portrayed as a passage that requires guidance, typically provided by a ferryman.