Scale 1 : 800,000.] Another lake basin lies to the south of the Zygos, between the alluvial lands of the Achelous and the Fidari. It is occupied by a swamp filled with fresh, brackish, or salt water; and since the days of ancient Greece, this swamp, owing to the apathy of the inhabitants, has continued to increase in extent at the expense of the cultivated land. Missolonghi the heroic is indebted for its name to its position near these marshes, for the meaning of it is “centre of marshes.” A barrier, or _ramma_, here and there broken through by the floods, separates the basin of Missolonghi from the Ionian Sea. During the war of independence every opening in this barrier was protected by redoubts or stockades, but at present the only obstruction consists of the reed barriers of the fishermen, which are opened in spring to admit the fish from the sea, and closed in summer to prevent their escape. Missolonghi, though surrounded by brackish water, is a healthy place, thanks to the breezes from the sea; whilst a heavy atmosphere charged with miasmata hangs perpetually over the bustling little town of Ætoliko (Anatolikon), which lies farther to the north-west in the midst of the swamps, and is joined to the dry land by two bridges. Between Ætoliko and the river Achelous may be observed a large number of rocky eminences, rising like pyramids above the plain. These are no doubt ancient islands, such as still exist between the mainland and the island of St. Mauro. The mud brought down by the Achelous has gradually converted the intervals between these {50} rocks into dry land. In former times the commercial city of Œniadæ occupied one of these islets. The geological changes already noticed by Herodotus are thus still going on under our eyes, and the muds of the Achelous, to which it owes its modern name of Aspro, or “white,” incessantly extend the land at the expense of the sea. [Illustration: Fig. 13.—THERMOPYLÆ. From the French Staff Map (1852). Scale 1 : 330,000.]