This paper analyses the description of the woods in the third act of Seneca’s Oedipus, where the silua, shaken by an earthquake, creates an opening between the earth and the underworld. The relationship between the woods and the underworld, which is confirmed by literary models (from Homer, to Vergil and Ovid), endows the landscape with a symbolic value and highlights the relationship between the tragedy of the protagonist and that of the city of Thebes, transformed by the plague into a kind of hell on earth. The conclusion also develops the hypothesis that the image of the wood, which is certainly more significant in Seneca’s Oedipus than in its direct Sophoclean hypotext, might allude to the Oedipus at Colonus, a play where landscape has a very important role as well.