The position of Abydos and Sestos, and the advantages of the situation of those towns it would, I think, be waste of time for me to state in great detail, because the singularity of those sites has made them familiar to all persons of intelligence. Still I imagine that it will not be otherwise than useful to remind my readers briefly of the facts, by way of attracting their attention. A man would best realise the advantages of these cities, not by regarding their sites by themselves, but by comparing and contrasting them with those about to be mentioned. For just as it is impossible to sail from the Ocean,—or as some call it the Atlantic,—into our sea, except by passing between the Pillars of Heracles, so is it impossible to sail from our sea into the Propontis and the Pontus except through the channel separating Sestos and Abydos. But as though Fortune had designed these two straits to counterbalance each other, the passage between the Pillars of Heracles is many times as broad as that of the Hellespont,—the former being sixty, the latter two stades; the reason being, as far as one may conjecture, the great superiority in size of the external Ocean to our sea: while the channel at Abydos is more convenient than that at the Pillars of Heracles. For the former being lined on both sides by human habitations is of the nature of a gate admitting mutual intercourse, sometimes being bridged over by those who determine to cross on foot, and at all times admitting a passage by sea. But the channel at the Pillars of Heracles is seldom used, and by very few persons, owing to the lack of intercourse between the tribes inhabiting those remote parts of Libya and Europe, and owing to the scantiness of our knowledge of the external Ocean. The city of Abydos itself is enclosed on both sides by two European promontories, and possesses a harbour capable of sheltering ships anchoring in it from every wind; while there is no possibility of anchoring at any point near the city outside the harbour mouth, owing to the rapidity and violence of the current setting through the strait. [Sidenote: Siege of Abydos.]