Vietri sul Mare is an Italian town of 8.328 inhabitants  of the province of Salerno in Campania.
UNESCO has declared since 1997 Vietri sul Mare (together with the other countries of the Amalfi Coast) a World Heritage Site.
It is located in front of the northern entrance of the city of Salerno, at the beginning of the Amalfi coast. The center of the town of Vietrese extends hilly close to the coast, and on the slopes of it extends the Marina area, a hamlet that overlooks the sea.
Vietri sul Mare is historically identified with the ancient Marcina, first Etruscan-Samnite coastal settlement, then Roman port.
The precise origin of Marcina is not yet completely defined even if the most widespread hypothesis indicates in Marina di Vietri, for its precision in the valley of the Bonea river at the foot of Monte San Liberatore, its presumed position.
The printed publication of the Marcina entry begins in the fifteenth century when the first typographical editions of Strabo's Geography began to spread in Europe; the real diffusion of the term among historians and publicists was with the geographer Filippo Cluverio, who in 1642 wrote: "Marcinae oppidum illud est, quonunc dicitur vulgo Veteri". Also some medieval documents of the "Codex Diplomaticus Cavensis" of the Abbey of Cava, which hint at the existence of ruins of a urbs vetus that would be the basis of today's toponym Vietri. In documents of 969 and 972 it is said "intus ipsa civitate, here fuit ipsa cibita de beteri (= veteri)"; in that of 972 it is specified that "de locum de beteri ista et illa part flubio Bonea iuxta litore maris".
The Vietri area, with the anchor of Fuenti, had a sheltered port, a unique port in the area, since the beach of nearby Salerno, near the mouth of the river, was exposed to the waves and subject to cover-up.
In light of this "nautical" consideration, the best security conditions would suggest, therefore, the mouth of the Bonea, and consequently Vietri, as an ideal site for the establishment of an Etruscan commercial emporium; moreover, in light of the geographic conformation of the territory, the only center on the sea is Vietri, to the south of Punta della Campanella, at a short distance from Nuceria Alfaterna.
Its history until 1806 was associated with that of Cava de 'Tirreni of which it was a fraction. Marina di Vietri, in fact, was used by the monks of the Badia as a trading port for exchanges especially with the areas south of Salerno, those of the "Piana del Sele".
From 1806 to 1860 it was the capital of the homonymous district belonging to the Salerno District of the Kingdom of the Two Sicilies.
From 1860 to 1927, during the Reign of Italy, it was the capital of the homonymous district belonging to the District of Salerno. Nowadays the municipality has a strong influence of Salerno, so there are plans to include Vietri sul Mare in the metropolitan area of this city.
In 1944, when Salerno was the capital of Italy for a few months, King Vittorio Emanuele III stayed in the nearby Villa Guariglia, located in the village of Raito.