The hero known for his journey to the underworld in Greek mythology is Orpheus. His tale centers on his love for Eurydice, who dies and descends to the underworld. Orpheus's enchanting music persuades Hades to allow him to bring her back to the living world. However, he is instructed not to look back at her until they reach the surface. When he does, Eurydice is lost forever, highlighting themes of love, loss, and the power of music in his tragic story.