Maru was one of Castello Monad's first wines: a monovarietal based on one of the area's leading native grapes, Negroamaro. There is an ongoing debate regarding the meaning of the name of this variety: some say it is a repetition of the word for "black" in two languages: "niger" in Latin and "mavros" in Greek; others believe that "amaro" (bitter) refers to the wine's grassy, often slightly rugged aftertaste. In Salento dialect, Maru means "austere", "dark", referring to the severe qualities expressed by the grape.