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
Christianity in the 15th century Christianity in the 15th century The 15th century is part of the High Middle Ages, the period from the coronation of Charlemagne in 800 to the close of the 15th century, which saw the fall of Constantinople (1453), the end of the Hundred Years War (1453), the discovery of the New World (1492), and thereafter the Protestant Reformation (1515). It also marked the later years of scholasticism and the growth of Christian humanism and other developments of the early Renaissance. The eastern Emperor John VIII Palaeologus, pressed hard by the Ottoman Turks, was keen to ally himself with the West,