There are innumerable stories of hidden cities in the desert near Siwa. This idea, and that of buried treasure, appeals strongly to an Oriental mind. Siwa itself, owing to its history, probably does contain a great deal that could be advantageously excavated. It is a field that would yield many treasures, as up to now no really thorough work has been carried out, though various people who have happened to be there have “done a little digging.” The ex-Khedive spent some money in uncovering some old ruins near one of the lakes, but really there is a great deal that has never been touched. Labour, and the difficulty of reaching Siwa, are the most formidable obstacles to any excavating projects. It is interesting to note that nearly all the mediæval Arab historians mention the emerald mines at Siwa, and in these days the natives still hold a belief in their existence. In the time of the Temple of Jupiter Ammon the figure of the god was decorated with emeralds, which were probably found in the country. According to a Siwan tradition there exists a cave in the hill called Gebel Dakrour, south of Aghourmi, which contains precious stones. But its entrance is guarded by a jinn, who makes it invisible except to a person who has drunk from the water of a certain spring among the sand-dunes south of Siwa. The spring is unknown in these days, but I have seen it marked on an old map of the desert. Possibly some of the peculiar shafts that pierce the hills round Siwa are the remains of old mines; it is difficult to imagine what else they could be. In 1048 the tribes of Hilal and Ben Soleim, who had been transported from Arabia as a punishment, and were living in the country between the Nile and the Red Sea, were given permission to cross the Nile and advance into Tripoli. Some 200,000 of them hastened like hungry wolves with their wives and families from Egypt to the west. They overran Tripoli and pushed on towards the shores of the Atlantic. It was some of these colonists who eventually forced Siwa to accept the Mohammedan rule, and by 1100, according to the Arab historians, the Koran flourished within the precincts of the Temple of Ammon. From that date onwards Siwa has been fanatically Mohammedan. The Siwans were not swept into oblivion by this great Arab invasion; apparently only a very few Arabs remained in the oasis, and very shortly they themselves became indistinguishable from the Siwans. From this time the Berbers, as a nation, ceased to exist, but they remained Berbers, not Arabs, and in a few out-of-the-way places, such as Siwa, they retained much of their original language.