We gradually ascended as we followed the valleys inland, after the Wadi Iroquis, until on the fourth day we came to a curious narrow winding pass, about six miles long, which just left room between the rocks for our camels to walk in single file. This pass, which is called Todin, landed us on a small plateau about 2,000 feet above the sea-level, where we found a large number of the circular remains. Todin is one of the most important approaches into the Soudan on the north side of the Erba group, and is practicable the whole way for camels, from which we never once had occasion to dismount, though going down might not be so pleasant. Before reaching the pass of Todin we passed a most curious mountain, seeming to block up the valley. It looked rather like a rhinoceros feeding among the acacia-trees. Taking this country generally, I can safely say it is as uninteresting and arid a country as any we have ever visited. Our way perpetually led through valleys winding between low brown mountains, the dry river beds of which were studded here and there with acacia-trees. Occasionally one got a glimpse of the majestic spurs of Erba, and occasionally a fantastic rock or a hill-slope a trifle greener than the rest would temporarily raise our spirits. As for water, we had the greatest difficulty about it, and our guides always enveloped its existence with a shroud of mystery. Men would be sent off to the hills with a camel, and return to the camp with skins of water from somewhere, probably from gulleys where rain-water still lay; but until we reached Wadi Hadai, after a ride of six days, we never saw water with our own eyes after leaving Hadi. More water can be obtained by digging. There is a great deal of _Mesembryanthemum_ about, which probably supplies the place of water to most of the animals living in these regions. A good many doves came to drink at the water in the evening. Two days more brought us to Wadi Hadai, where we were to halt awhile to rest the camels. On the hill immediately above us was the circular fort, with its door to the east, to which I shall later allude, and on the plain below was another and smaller Kufic tower, several round buildings, and large stones erected on several of the adjacent hills evidently to act as landmarks. Also here we saw many graves of the Debalohp family--neat heaps of white stones, with a double row of white stones forming a pattern around them, and a headstone towards Mecca, on one of which was a rude Arabic inscription. These tombs reminded us very forcibly of the Bogos tombs in Northern Abyssinia, and evidently point to a kinship of custom. The place where we stayed in a wood of thorny trees was at the branching of two valleys. We always had cold nights, but our widely spread camp looked cheery enough with eight fires; there were so many different parties.