Of the early sites in the region of the Shatt el-Kâr the mounds at Fâra have been the most productive of remains dating from the prehistoric period of Sumerian culture. Systematic excavations were begun here by Dr. Koldewey in 1902,[14] and were continued in the following year by Drs. Andrae and Noeldeke.[15] The accompanying plan will give some idea of the extensive area occupied by the mounds, and of the method adopted for ascertaining their contents without too great an expenditure of time. The Arabic numerals against the contour lines indicate their height in metres above the level of the plain. Roman figures are set at each end of the trenches in the order in which they were cut. Thus the first two trenches (I. and II.), running from north to south and from east to west respectively, were cut across the mounds by Dr. Koldewey to gain some idea of their general character. The subsequent trenches were all cut parallel to the second through the higher portions of the site, a few of them being extended so as to cover the lower detached mounds to the east. In the plan the trenches are marked as continuous, but actually each consists of a series of short sections, divided by bands of soil left uncut. These hold up the sides of the trench and leave passages for crossing from one side to the other.[16] Whenever a trench discloses the remains of a building it can be completely uncovered and the trench afterwards continued until another building is disclosed. In the plan the principal cleared areas are outlined, and the position of walls which were uncovered within them is indicated by fine lines. [Illustration: FÂRA after Andrae and Noeldeke]