A famous lake occupies the bottom of the limestone basin at the western foot of the mountain mass of Metzovo. This is the Lake of Yanina, and nowhere else throughout Epirus do we meet with an equal number of natural curiosities as on the shores of this lake. Its depth is inconsiderable, nowhere exceeding forty feet, and it is fed only by numerous springs rising at the foot of the rocks. There is no {117} visible outlet; but Colonel Leake assures us that each of the two basins into which it is divided is drained by a subterranean channel. The northern lake pours its waters into a sink, or _voinikova_, and reappears towards the south-west as a considerable river, which flows into the Ionian Sea. This is the Thyamis of the ancients, our modern Kalamas. Farther to the south the ancient Acheron bursts from the rocks, and having received the nauseous waters of the equally famous Cocytus, throws itself into the “bay of sweet waters,” thus called on account of the large volume of water discharged into it by rivers. [Illustration: Fig. 36.—SOUTHERN EPIRUS. According to Kiepert. Scale 1 : 1,400,000. K. Katavothra.] When the waters of the southern and larger basin of Lake Yanina are low, there is but a single effluent, which plunges down into an abyss, and in doing so turns the wheels of a mill. The Cyclopean ruins of the Pelasgic city of Hellas command this huge chasm with its roaring waters. The subterranean river reappears far to the south, and flows into the Gulf of Arta. But when the level of the lake is high, four other sinks swallow up its superabundant waters, and convey them into the main channel, the direction of which is indicated by a few small lakes. The important part played in the mythology of ancient Greece by these subterranean effluents, and particularly by the infernal Acheron and the Cocytus, amply proves the influence exercised by the Pelasgians upon the civilisation of the Hellenes. The myths of the Hellopians became the common property of all Greece, and {118} there was no temple in all Hellas more venerated than their sanctuary at Dodona, where the future might be foretold by listening to the rustling of the leaves of sacred oaks. This sacred grove existed, probably, near one of the Cyclopean towns so numerous in the country, if not on the shore of the lake itself. Some, erroneously no doubt, have looked for it near the castle inhabited in the beginning of this century by Ali Tepeleni, the terrible Pasha of Epirus, who boasted of being a “lighted torch, devouring man.”