Commanding as it does the entrance to the valley of Torontoy, Salapunco may have been built by some ancient chief to enable him to levy tribute on all who passed. My first impression was that the fortress was placed here, at the end of the temperate zone, to defend the valleys of Urubamba and Ollantaytambo against savage enemies coming up from the forests of the Amazon. On the other hand, it is possible that Salapunco was built by the tribes occupying the fastnesses of Uilcapampa as an outpost to defend them against enemies coming down the valley from the direction of Ollantaytambo. They could easily have held it against a considerable force, for it is powerfully built and constructed with skill. Supplies from the plantations of Torontoy, lower down the river, might have reached it along the path which antedated the present government road. Salapunco may have been occupied by the troops of the Inca Manco when he established himself in Uiticos and ruled over Uilcapampa. He could hardly, however, have built a megalithic work of this kind. It is more likely that he would have destroyed the narrow trails than have attempted to hold the fort against the soldiers of Pizarro. Furthermore, its style and character seem to date it with the well-known megalithic structures of Cuzco and Ollantaytambo. This makes it seem all the more extraordinary that Salapunco could ever have been built as a defense against Ollantaytambo, unless it was built by folk who once occupied Cuzco and who later found a retreat in the canyons below here. ------ FIGURE Grosvenor Glacier and Mt. Salcantay ------ When we first visited Salapunco no megalithic remains had been reported as far down the valley as this. It never occurred to us that, in hunting for the remains of such comparatively recent structures as the Inca Manco had the force and time to build, we were to discover remains of a far more remote past. Yet we were soon to find ruins enough to explain why such a fortress as Salapunco might possibly have been built so as to defend Uilcapampa against Ollantaytambo and Cuzco and not those well-known Inca cities against the savages of the Amazon jungles.