"El túnel" is a novel written by Argentine author Ernesto Sabato, published in 1948. The story follows the psychological journey of Juan Pablo Castel, a painter who becomes obsessed with a woman named María. The narrative explores themes of isolation, existentialism, and the darker aspects of human nature. The novel is set in Buenos Aires and is told from Castel's perspective, revealing his inner thoughts and motivations. As Castel's obsession grows, he becomes increasingly unstable, leading to tragic consequences. "El túnel" is considered a significant work in Latin American literature, reflecting the complexities of the human psyche.