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 northwest edge of the rock platform points out the Solstice Window to within 2’ of the 15th century June solstice rising Sun. For comparison, the angular diameter of the Sun is 6'. The Inca constellation Qullca, storehouse, can be viewed out the Qullqa Window at sunset during the 15th century June Solstice, hence the window's name. At the same time, the Pleaides are in the opposite end of the sky. Also seen through this window on this night are the constellations Llamacnawin, Llama, Unallamacha, Machacuay, and the star Pachapacariq Chaska (Canopus). The "Intihuatana" stone is one of many ritual stones