Terraces at Ollantaytambo

The valleys of the Urubamba and Patakancha rivers along Ollantaytambo are covered by an extensive set of agricultural terraces which start at the bottom of the valleys and climb up the surrounding hills. The terraces permitted farming on otherwise unusable terrain; they also allowed the Incas to take advantage of the different ecological zones created by variations in altitude. Terraces at Ollantaytambo were built to a higher standard than common Inca agricultural terraces, for instance, they have higher walls made of cut stones instead of rough fieldstones. This type of high-prestige terracing is also found in other Inca royal estates such as Chinchero, Pisaq, and Yucay.

A set of sunken terraces start south of Ollantaytambo's Plaza de Armas, stretching all the way to the Urubamba River. They are about 700 meters long, 60 meters wide and up to 15 meters below the level of surrounding terraces; due to their shape they are called Callejón, the Spanish word for alley. Land inside Callejón is protected from the wind by lateral walls which also absorb solar radiation during the day and release it during the night; this creates a microclimate zone 2 to 3°C warmer than the ground above it. These conditions allowed the Incas to grow species of plants native to lower altitudes that otherwise could not have flourished at this site.

At the southern end of Callejón, overlooking the Urubamba River, there is an Inca site called Q'ellu Raqay. Its interconnected buildings and plazas form an unusual design quite unlike the single-room structures common in Inca architecture. As the site is isolated from the rest of Ollantaytambo and surrounded by an elaborate terraces, it has been postulated that it was a palace built for emperor Pachacuti.