This monument was long believed to be a Roman =gate=--hence its name--although the ornamentation of its four sides proves that it cannot originally have been connected with the ramparts. It was only in the Middle Ages that it was included in the fortified castle (_photo, p. 6_) built by the archbishops a few steps to the rear. About 1334 its arcades were walled up, while towards 1554 it was buried under a mass of rubbish during the building of the fortifications. Partly disinterred in 1594, when the archbishops' castle was pulled down, it was not completely cleared until 1816-1817. Restored, then classed as an _historical monument_ (thanks to Prosper Mérimée), it is one of the largest Roman structures remaining in France. Forty-four feet high, one hundred and eight wide, and sixteen thick, it was really a triumphal arch built on the Cæsarean Way at the entrance to the town, probably in the 4th century. It comprises three arches separated by fluted Corinthian columns which support the entablature. On the two main façades between the columns are carved medallions and niches which have lost their statues. The vaulting of the arches is divided into sunken panels, the carving of which is mostly in a good state of preservation. Under the eastern arch _Romulus and Remus_ are seen suckled by the she-wolf. Under the middle arch, the twelve months of the year, represented by persons (five of whom have been destroyed), occupied in the labours of the four seasons, surround Abundance and Fortune. Under the western arch Love is seen descending from the sky above Leda and the Swan. [Illustration: HÔTEL NOËL DE MUIRE _Note the curious masonry-work of the first storey, composed of polygonal stones in relief._] _Behind the Mars Gate is the Place de la République, containing_ a statue by Bartholdi, damaged by shell-fire. _In front of the Gate, take the Rue Henri IV., leading behind the Hôtel-de-Ville, then turn to the left into the Rue de Sedan._ The house at No. 3 was destroyed by shells, except the =Louis XVI. front= with its gracefully carved garlands, which escaped injury. _Take the Rue du Grenier-à-Sel, on the right, to the_ =Hôtel Noël de Muire=, _on the left, at the corner of the Rue Linguet._ This house consists of the remains of a sort of Henry II. manor with turrets and dormer-windows. The walls, rounded at the corners like those of the Templars, are of brick and dressed stone. The plinth separating the two stories is decorated with carved wreathed foliage. Fret-work and hexagonal points frame the windows, while a broad cornice on consoles carries the roof. Formerly the residence of the lords of Muire, this house was popularly known as the _Maison des Petits Pâtés_, on account of the polygonal shape of the stones in relief. Theodore de Bèze, one of the leaders of the Reformation in France, lived there with his friend, Noël de Muire. [Illustration: THE RUE DU MARC] _Take the Rue du Marc, which continues the Rue du Grenier-à-Sel (photo above)._