Until 1951,th e great archaeological site we now call Surkh Kotal had completely escaped notice. In the autumn of that year, a friend of mine, Sarwar Nasher Khān, informed me that some stones bearing Greek letters had just been found in Northern Afghanistan by a team of workers engaged in building a new road. A few weeks later, we visited the site. It lay some 15 km. to the north-west of Pul-i Khumri, and some 12 km. to the south of Baghlān, two modem industrial centres in the valley of the Kunduz River. Having asked for the find spot, we were shown a ruined structure bordering the new road, at the bottom of a hill (henceforth called ‘ the acropolis ’) projecting like a promontory into the valley, and we could see at once that this structure was but a part of a large fortified enclosure of irregular shape following the contours of the hill-area. Inside this enclosure could be seen a smaller rectangular enclosure, the centre of which was occupied by a large flat-topped mound. Several architectural fragments were lying about. They were made of the local limestone. They included two big column-bases, and what appeared to be the remains of a mighty stele in alto-relievo, 2.20 m. high. Inquiring about the name of the place, we got several contradictory answers, two things only being clear : (1) that the place was a ‘ Kafir Kala ’, a ‘ Heathen’s Castle ’; and (2) that the saddle or pass connecting the hill with the mountains further west was called Surkh Kotal, ‘ The Red Pass ’. In fact the ruin was anonymous, but ‘ Heathen’s Castle, of the Red Pass ’ could be considered a suitable name. We shortened it into ‘ Surkh Kotal ’, ‘ The Red Pass ’.