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 the site is often interpreted as "old mountain". Machu Picchu was built around 1450–1460. Its construction appears to date to the period of the two great Inca rulers, Pachacutec Inca Yupanqui (1438–71) and Túpac Inca Yupanqui (1472–93). There is a consensus among archaeologists that Pachacutec ordered the construction of the royal estate for himself, most likely after his successful military campaign. Though Machu Picchu is considered to be a "royal" estate, surprisingly, the estate would not have been passed down in the line of succession. It was only used for approximately 80 years before being abandoned seemingly due to destruction