Some have identified it with Ajrud, a fortress between Etham and Suez. The condition of the Isthmus of Suez at the time of the Exodus is not exactly known, and hence this, with the other places mentioned as encampments of Israel in Egypt, cannot be definitely ascertained. The isthmus has been formed by the Nile deposits. This increase of deposit still goes on, and so rapidly that within the last fifty years the mouth of the Nile has advanced northward about four geographical miles. In the maps of Ptolemy (of the 2nd and 3rd centuries A.D.) the mouths of the Nile are forty miles further south than at present.