A little more than a quarter of a mile west of the Acropolis is another rocky hill—­the Pnyx—­celebrated as the place where the assembly of all the citizens met to transact the business of the state.  A large semicircular area was formed, partly by excavation, partly by building up from beneath, the bounds of which can be distinctly traced.  Considerable remains of the terrace-wall at the foot of the slope exist—­huge stones twelve or fourteen feet in length by eight or ten in breadth.  The chord of the semicircle is near the top of the hill, formed by the perpendicular face of the excavated rock, and is about four hundred feet in length by twenty in depth.  Projecting from it at the centre, and hewn out of the same rock, is the bema or stone platform from which the great orators from the time of Themistocles and Aristides, and perhaps of Solon, down to the age of Demosthenes and the Attic Ten, addressed the mass of their fellow-citizens.  It is a massive cubic block, with a linear edge of eleven feet, standing upon a graduated base of nearly equal height, and is mounted on either side by a flight of nine stone steps.  From its connection with the most celebrated efforts of some of the greatest orators our race has yet seen, it is one of the most interesting relics in the world, and its solid structure will cause it to endure as long as the world itself shall stand, unless, as there is some reason to apprehend will be the case, it is knocked to pieces and carried off in the carpet-bags of travelers.  No traces of the Agora, which occupied the shallow valley between the Pnyx and the Acropolis, remain.  It was the heart of the city, and was adorned with numerous public buildings, porticoes, temples and statues.  It was often thronged with citizens gathered for purposes of trade, discussion, or to hear and tell some new thing.

[Illustration:  PORCH OF THE CARYATIDES.]

Half a mile or more to the south-east, on the banks of the Ilissus, stood a magnificent structure dedicated to Olympian Zeus—­one of the four largest temples of Greece, ranking with that of Demeter at Eleusis and that of Diana at Ephesus.  Its foundations remain, and sixteen of the huge Corinthian columns belonging to its majestic triple colonnade.  One of these is fallen.  Breaking up into the numerous disks of which it was composed—­six and a half feet in diameter by two or more in thickness—­and stretching out to a length of over sixty feet, it gives an impressive conception of the size of these columns, said to be the largest standing in Europe.  The level area of the temple is now used as a training-ground for soldiers.  Close by, and almost in the bed of the stream, which is dry the larger part of the year, issues from beneath a ledge of rock the copious fountain of sweet waters known to the ancients as Calirrhoe.  It furnished the only good drinking-water of the city, and was used in all the sacrifices to the gods.  A little way above, on the opposite bank of the Ilissus, is the site of the Panathenaic stadium, whose shape is perfectly preserved in the smooth grass-grown hollow with semicircular extremity which here lies at right angles to the stream, between parallel ridges partly artificial.