La Leyenda de la Llorona is a popular Mexican folktale about a woman named María who, after losing her children, wanders near rivers and lakes, crying for them. The story varies by region, but it often depicts her as a tragic figure who is doomed to search for her lost children for eternity. The legend serves as a cautionary tale, warning children to stay away from water at night. Many believe that hearing her cries is an omen of misfortune. Over time, La Llorona has become a symbol of grief and loss in Mexican culture, inspiring various adaptations in literature and film.