The natural advantages [of a place] should always be mentioned, since they are permanent. Advantages which are adventitious are liable to change, although the majority of those which have continued for any length of time should not be passed over, nor even those which, although but recent, have yet acquired some note and celebrity. For those which continue, come to be regarded by posterity not as works of art, but as the natural advantages of the place; these therefore it is evident we must notice. True it is, that to many a city we may apply the reflection of Demosthenes[756] on Olynthus and its neighbouring towns: “So completely have they vanished, that no one who should now visit their sites could say that they had ever been inhabited!” Still we are gratified by visiting these and similar localities, being desirous of beholding the traces of such celebrated places, and the tombs of famous men. In like manner we should record laws and forms of government no longer in existence, since these are serviceable to have in mind, equally with the remembrance of actions, whether for the sake of imitating or avoiding the like. 18. Continuing our former sketch, we now state that the earth which we inhabit contains numerous gulfs, formed by the exterior sea or ocean which surrounds it. Of these there are four principal. The northern, called the Caspian, by others designated the Hyrcanian Sea, the Persian and Arabian Gulfs, formed by the [Southern] Sea, the one being nearly opposite to the Caspian, the other to the Euxine; the fourth, which in size is much more considerable than the others, is called the Internal and Our Sea.[757] It commences in the west at the Strait of the Pillars of Hercules, and continues in an easterly direction, but with varying breadth. Farther in, it becomes divided, and terminates in two gulfs; that on the left being called the Euxine Sea, while the other consists of the seas of Egypt, Pamphylia, and Issus. All these gulfs formed by the exterior sea, have a narrow entrance; those of the Arabian Gulf, however, and the Pillars of Hercules are smaller than the rest.[758] The land which surrounds these, as before remarked, consists of three divisions. Of these, the configuration of Europe is the most irregular. Libya, on the contrary, is the most regular; while Asia holds a middle place between the two. In all of these continents, the regularity or irregularity of form relates merely to the interior coasts; the exterior, with the exception of the gulfs before mentioned, is unindented, and, as I have stated, resembles a chlamys in its form; any slight differences being of course overlooked, as in large matters what is insignificant passes for nothing. Since in geographical descriptions we not only aim at portraying the configuration and extent of various places, but also their common boundaries, we will remark here, as we have done before, that the coasts of the Internal Sea[759] present a