Dry stone from the arable or cultural land. They serve both as cattle/sheep fences and the lot's borders. Sometimes also the dry stone terracing is apparent, often combined with parts of stone masonry (house foundations and shed walls) that are held together by a clay-cum-needles "composite" mortar. In Peru in the 15th century AD, the Inca made use of otherwise unusable slopes by building dry stone walls to create terraces. They also employed this mode of construction for freestanding walls. Their ashlar type construction in Machu Picchu uses the classic Inca architectural style of polished dry-stone walls of regular shape. The Incas
Machu Picchu Spanish never found Machu Picchu and so did not plunder or destroy it, as they did many other sites. The conquistadors had notes of a place called "Piccho", although no record of a Spanish visit exists. The types of sacred rocks defaced by the conquistadors in other locations are untouched at Machu Picchu. Over the centuries, the surrounding jungle overgrew the site, and few outside the immediate area knew of its existence. The site may have been discovered and plundered in 1867 by a German businessman, Augusto Berns. Some evidence indicates that German engineer J. M. von Hassel arrived earlier.