Undoubtedly the system of approach to the Indus valley, open to Arab traffic from Syria and Bagdad, most generally used and most widely recognized was that through the Makran valleys to Karachi and Sind, whilst the inland route, _via_ Persia and Seistan, made the well-known ford of the Helmund at Girishk, or the boat bridge at Kala Bist, its objective, and passed over the river to the plains about Kandahar. But it is a very remarkable, and possibly a significant, fact that the continuation of the route to Sind and the Indus valley from the plains about Kandahar is not mentioned by any Arab writer. Did the Arabs descend through any of the well-known passes of the frontier--the Mulla, Bolan, Saki-Sarwar, or Gomul--into the plains of India? Possibly they did so; but in that case it is difficult to account for so important a geographical feature as the frontier passes of Sind being ignored by the greatest geographer of his day. Following Idrisi's description of the Helmund province we have a brief itinerary from the Helmund ford (Derthel or Benjawai) to Ghazni, said to be nine days' journey inland. None of the places mentioned are to be identified in modern maps except Cariat, which is more than probably Kariut, a rich and fertile district in the Arghandab valley in the direct line to Kalat-i-Ghilzai. This route passes well to the north-east of Kandahar, which was apparently of little account in Idrisi's days. Although there are extensive ruins at Kushk-i-Nakhud, indicated by a huge artificial mound half-way between Girishk and Kandahar, there is nothing in Idrisi's writings by which they can be identified. Ghazni was then a large town "surrounded by mud walls and a ditch. There are many houses and permanent markets in Ghazni; much business is done there. It is one of the 'entrepots' of India. Kabul is nine days' journey from it." This is not much to say of the city which had been enriched by the spoils carried away from Muttra and Somnath, and by the treasures amassed during seventeen fierce raids of that Mahmud who, by repeated conquests, made all Northern and Western India contribute to his treasury. Later, in 1332, the Arab traveller, Ibn Batuta, writes of Ghazni as a small town set in a waste of ruins--a description which fits it not inaptly at the present day; but in Idrisi's time, before the wars with Ghur led to its destruction, whilst still the wealth of a great part of India supported its magnificence, and whilst it was still the theme of glowing panegyric by contemporary historians, one would expect a rather more enthusiastic notice. But even Kabul (nine days' journey distant from Ghazni) is only recognized as "_L'une des grandes villes de l'Inde, entourée de murs_," with a "_bonne citadelle et au dehors divers faubourgs_."[5]