The ancient Roman colony of "Portus Lunae" was founded in 177 BC at the mouth of the Magra river after bitter battles against the Ligurians for the conquest of the territory. The city became a prosperous center and had a very long life until the thirteenth century, when its decline (the floods of the Magra river changed the plain by moving the coastline much further) was mentioned by Dante Alighieri in the XVI Canto del Paradiso.

The prosperity of Luni, due to the direct management of the marble quarries - today called Carrara but which in Roman times was called "Lunense" - and its trade, is still recognized today in the luxury of the ancient mosaics of the domus, in the wall frescoes and in the majesty of public and religious buildings.

The city of Luni, surrounded by walls and facing the sea, was organized in elongated rectangular blocks and had a large public area, the forum, in which the cardo and decumanus intersected and are still partially accessible today. The Capitolium dedicated to the Capitoline triad Jupiter, Juno and Minerva overlooked the forum; further north was the Great Temple, dedicated to the cult of the Moon goddess. The tour ends with a visit to the extraordinary imperial amphitheater still preserved today in its main structures.