The culture at Anau is very similar in all its essentials to that of the European lake-dwellers, and is much older. The same cereals and the same kinds of domesticated animals appear in both. The brick houses are better and the very fine painted pottery is new and peculiar. These and the art of spinning and the cultivation of cereals were brought hither by the first settlers; their development to this stage must have taken place elsewhere and occupied a long period of time. Sheep could not have been domesticated here, for they and the goats are natives of the mountains, and could not survive wild on the steppe. Neither is the pig a steppe animal, but lives naturally in forest glades and along watercourses. Pumpelly has evidently discovered a very old and interesting station in the spread of this ancient culture, but not its cradle. This was apparently in some mountainous region. The nearest and most likely place to search for it is somewhere on the Iranian plateau, to which the turquoise bead and the later-introduced copper and lead found at Anau also point. Here at Susa (Shushan), about one hundred miles from the apex of the Persian Gulf, de Morgan excavated in a mound rising about thirty-four metres above the level of the plain and continuing some six metres below the surface, which has been raised that amount since the first settlement was made.[77] The total thickness of the remains is therefore about forty metres. The lowest strata as yet have been only slightly studied. The uppermost ten to fifteen metres cover a period of about 6,000 years. If the lower strata were accumulated at the same rate, the first settlement was begun about 18,000 years ago at a conservative estimate. Montelius, the best authority on European prehistoric chronology, basing his conclusions on de Morgan's discoveries, places the date of the beginning of Neolithic culture in this part of Asia at about 18,000 B. C., or somewhat earlier.[78] Over twenty metres of these remains are purely Neolithic. There was the usual abundance of flint nuclei, flakes, and utensils. There was obsidian, evidently brought from a distance--de Morgan thinks from Armenia, a thousand miles away. This is not impossible; we shall find that trade or barter was far more extensive at this time than has usually been supposed.