GIANNUTRI (Gr. Ἀρτεμίσιον, Lat. Dianium), an island of Italy, about 1 sq. m. in total area, 10 m. S.E. of Giglio and about 10 m. S. of the promontory of Monte Argentario (see Orbetello). The highest point is 305 ft. above sea-level. It contains the ruins of a large Roman villa, near the Cala Maestra on the E. coast of the island. The buildings may be divided into five groups: (1) a large cistern in five compartments, each measuring 39 by 17 ft.; (2) habitations both for the owners and for slaves, and store-rooms; (3) baths; (4) habitations for slaves; (5) belvedere. The brick-stamps found begin in the Flavian and end with the Hadrianic period. The villa may have belonged to the Domitii Ahenobarbi, who certainly under the republic had property in the island of Igilium (Giglio) and near Cosa.

See G. Pellegrini in Notizie degli scavi (1900), 609 seq.