The main settlement at Ollantaytambo has an orthogonal layout with four longitudinal streets crossed by seven parallel streets. At the center of this grid, the Incas built a large plaza that may have been up to four blocks large; it was open to the east and surrounded by halls and other town blocks on its other three sides. All blocks on the southern half of the town were built to the same design; each comprised two "kancha", walled compounds with four one-room buildings around a central courtyard. Buildings in the northern half are more varied in design; however, most are in such a bad condition that their original plan is hard to establish.