At Ollantaytambo, in the Cusco region of Peru, the Inka (c. AD 1400–1532) built an elaborate anthropogenic landscape to facilitate intensive agriculture. After the 1532 Spanish invasion of the region, this landscape was reshaped by the introduction of new plants and animals, colonial land-management practices and demographic transformations. Here, the author employs botanical data from a derelict Inka-era reservoir to evaluate the timing and character of colonial transformations to the local agroecology. These transformations, they argue, tended towards agricultural deintensification, but this process did not begin until decades after the Spanish invasion.