These lagunes formed convenient and safe harbours for the early Phœnicians and other navigators, and were suitable in depth for the size of the craft then in use. But gradually the floods of the rivers brought down more deposits, and even in Roman times threatened to block up the passages through the lagunes to the open sea. It was only by building a strong wall for the purpose of forcing the river Aude to keep in a certain channel, so that when in flood it might scour out the passage, and by the erection of beacons in the lagune to mark the navigable course, that the Roman port of Narbonne could be kept open. In 1320 a great flood destroyed the retaining wall and changed the course of the river, after which the ruin of Narbonne as a seaport was complete. The town is now 8 miles from the sea, and is connected with “la Robine” branch of the Canal du Midi, which unites the Mediterranean with the Bay of Biscay. A similar process to that at Narbonne has contributed to the ruin of several other ancient towns in this province,--a district which has also suffered more severely than any other at the hands of the Saracens. Forming as it does the easiest access from Spain into Provence, it necessarily lay open to constant attack. Besides, the Moors, although driven across the Pyrenees, were still masters of the sea, and as corsairs or pirates they scoured the Mediterranean for many centuries after the time of C. Martel, attacking and plundering the smaller towns all round the coast, and in some instances fortifying themselves on land in strong places whence they could issue to plunder the more inland country. Such was their establishment at the Grand Fraxinet, in the mountainous district lying to the east of Toulon, which is still known as the “chaine des Maures.” We shall have occasion to observe some architectural effects resulting from their invasions, particularly how the inhabitants were forced to seek refuge on the rocky heights, and to build their towns on the top of almost inaccessible mountains. The Moors have also left traces of their presence both in the general design and details of several of the edifices of the Western Riviera. Proceeding westwards from Marseilles by rail and passing St Gilles, we reach Montpellier, the architecture of which is chiefly modern. The ancient church of Maguelonne, situated on the outer boundary of the lagunes, may however, be visited from here. It was fortified and not unlike that of the Stes. Maries. Omitting for the present the wonderful town of Aigues-Mortes, to which we shall again return, we continue our journey amongst the lagunes, past the crowded modern seaport of Cette, and the ancient town of Agde, with its dark church crowned with frowning fortifications, and at last reach Béziers, a place whose architecture claims our attention.