LUNA (mod. Luni)  , an ancient city of Etruria, Italy, 42 M . S.E. of the modern Sarzana . It was the frontier town of Etruria, on the left bank of the river, Macra, the boundary in imperial times between Etruria and Liguria . When the Romans first appeared in these parts, however, the Ligurians were in possession of the territory as far as Pisa . It derived its importance mainly from its harbour, which was the gulf now known as the Gulf of Spezia, and not merely the estuary of the Macra as some authors have supposed . The town was apparently not established until 177 B.C., when a colony was founded here, though jhe harbour is mentioned by Ennius, who sailed hence for Sardinia in 205 B.C. under Manlius Torquatus . An inscription of 155 B.C., found in the forum of Luna in 1857, was dedicated to M . Claudius Marcellus in honour of his triumph over the Ligurians and Apuani .