At either extremity of the plain is a marsh. That on the north-east is very extensive, reaching from the mountains all but to the sea. That on the south-west is small; but being at the extreme end of the plain where Mount Agrieliki comes within a half or three-quarters of a mile from the coast, it renders the passage from the south along the foot of this hill very narrow. This little marsh, though, of course, much drier in summer than in winter, was not, I should say, traversable in August, 1899; and this, too, after a prolonged period of drought. The interval between the two marshes is a little more than three miles.

The interval of ground is traversed near its centre by the torrent known as the Charadra, the bed of which is sufficiently marked to form an appreciable military obstacle.

Herodotus’ description of Marathon is noticeable for its absence of topographical detail, and in this respect is in strong contrast with his descriptions of Thermopylæ and Platæa. Topographically speaking, he knows more even of Mykale than he does of Marathon.

There is, in fact, no evidence, direct or indirect, of his ever having visited the field; and the absence of all descriptive detail is strong presumptive evidence that he never had done so.

This may be simply due to the fact that Marathon, unlike Thermopylæ and Platæa, is not on any of the main roads of Greece; but, as it is only twenty-four miles from Athens, and as Herodotus shows himself peculiarly anxious to give topographical details wherever he is describing events of first-rate importance, it would seem as if he did not regard Marathon as being of so much significance as the Athenians made it out to have been. Of purely physical features he says not a word. Of other details he simply mentions the place of the encampment of the Athenians, the sacred precinct of Herakles, the site of which has been discovered high up that valley of Avlona which leads up among the hills from the south-west verge of the plain.

South of the Charadra the plain is highly cultivated, mainly with the vine. If it was so in 490 B.C., it would not have been by any means unimpeded ground for cavalry, as the Greek habit of allowing the vine-tendrils to run along the surface renders the vineyards of the country troublesome, if not dangerous, obstacles to the passage of a mounted man going at more than a foot’s pace. North of the Charadra the cultivation is more sparse and the ground more open.

From the plain two roads lead to Athens:

(1) An upper one, which leaves the plain in two branches, one of which goes up the valley of the Charadra past the modern Marathona, and then bends W.S.W. through the hills in the direction of Athens. About a mile and a half beyond Marathona it is joined by the second branch, which, leaving the plain near the modern Vrana, goes up the valley of Avlona and through the site of the precinct of Herakles, which is situated near, though not at the point of junction of the two. From this point the road proceeds over the mountains, and, passing the modern Stamata, descends into the Athenian plain near Kephisia, whence it goes direct to Athens. It is a rugged track, though not very difficult, and is certainly that which was used by the Athenians in their advance to Marathon.