On leaving for India to accompany the army into Afghanistan in 1878, Colonel Yule, among other hints of places of interest of an archæological character to be looked out for, mentioned Nagarahara, the capital of the Jelalabad Valley in the Buddhist period. In the time of Hiouen-Thsang the district bore the same name as the capital, and it had no king of its own, but belonged to Kapisa, a city situated somewhere in the direction of Kabul. The district of Nagarahara extended to about 600 Chinese Li, from east to west, which would be over 100 miles. This might reach from about Jugduluck to the Khyber, so that in this last direction it would thus border on Gandara, and on the other extremity would touch Kapisa, which was also the name of the district as well as the capital of that name. The Valley of Jelalabad is small in comparison to that of the province which formerly belonged to it. From Darunta on the west to Ali-Boghan on the east is fifteen miles, but, on the left bank of the Kabul River, the flat land of Kamah extends the valley on that side, about five or six miles further to the east. The termination of the Valley at this place is called Mirza Kheyl, a white rocky ridge comes down close to the river, and there are remains of Buddhist masonry on it, with caves in the cliff below. On the right bank opposite Mirza Kheyl is Girdi Kas, which lies in a small valley at the northern end of a mass of hills which terminates the Jelalabad Valley on that side at Ali-Boghan, separating it from the Chardeh Plain, which again extends as far as Basawul. I got a kind of bird's-eye view of this one day from a spur of the Sufaid Koh, 8,000 feet high, near to Gundumuck, and the Jelalabad Valley and the Chardeh Plain seemed to be all one, the hills at Girdi Kas appearing at this distance to be only a few slight mounds lying in the middle of this space, which would be altogether about 40 miles in extent. When in the Jelalabad Valley, the Girdi Kas hills are undoubtedly the eastern barrier, while the Siah Koh Range is the western. The Siah Koh Range trends to the south-west, and then turns due west, forming a distinct barrier on the north till it is lost at Jugduluck; there are only some low-lying ridges between Futteeabad and Gundumuck, but they are so small that it might be said to be a continuous valley all the way from Ali-Boghan to the plain of Ishpan. The eastern end of the Siah Koh Range terminates at Darunta, which is the north-west corner of the Jelalabad Valley. The Kabul River, instead of going round the extreme end of this range, has, by some curious freak, found a way through the rocky ridge so close to the extremity, that it leaves only what might be called one vertebra of this stony spine beyond. The river here has formed for itself a narrow gorge through perpendicular cliffs, in which it flows, from the district of Lughman, into the level plain of the Jelalabad Valley. The Surkhab pours down from the Sufaid Koh, starting close to Sikaram, the highest point of the range, which our surveyors found to be 15,600 feet above the sea. It passes over the western end of the Ishpan plain, towards the Siah Koh Range, and it then keeps to the contour of its base all the way to the Jelalabad Valley, and joins the Kabul River about two miles below Darunta.
Labels on the maps of the Third Military Survey of Austria-Hungary and on the survey maps of the Military Geographical Institute (Wojskowy Instytut Geograficzny) in Warsaw in the light of survey manuals