The builders of Machu Picchu must have worked hard to achieve an architectural equilibrium with such a special and difficult environment. To build the citadel they used materials from the surroundings, stone blocks taken from the border areas. Moreover, the construction itself was the result of an incredible architectural planning for that time.

The ancient Peruvians built it at the back of a spur called Machupicchu, taking advantage of the low mountainsides and the very small plateau on this great stone block, which is part of a rocky outcrop of volcanic origin, of more than a hundred square kilometers surface area.

On this steep, short and uneven surface, the Incas had to design a complex that lacked the characteristics of a conventional city. Some specialists point out that the urban design of the citadel and its surroundings, containing elements that form part of the Andean view (major mountains and rocks, caves and springs), reinforce the idea that it was a sanctuary.

Practically all places that exist inside the Historical Sanctuary of Machu Picchu suggest the existence of the same creative idea and the same building style. The visitor immediately notices the recurrent use of a series of typical Inca elements, showing a manifest intention of integrating its splendid architecture with the extraordinary natural items surrounding it.

All the buildings in Picchu follow the Inca classic architectural style: buildings with irregular walls, perfect joints between the stone blocks and a gentle slope, making the base slightly wider than the top. Gates with a trapezoidal shape and niches and sculptures are used as part of the architectural design and decoration.

The finish of the walls presents different qualities, and reveals an exquisite technique for attaching the blocks, as can be observed in the central wall of the Main Temple, one of the best achieved walls. Machu Picchu encroaches on the hills, on whose peaks the Incas built ceremonial altars, expressing the sacred character of all the area, as well as the great spirituality of the Incas, and their religious ideas expressed in their architecture and depicted in colossal blocks of stone.

Machu Picchu may also be known as the "citadel of the platforms, stairways and water fountains". There are more than a hundred stairs, some with a hundred steps or more. In some cases an eight or ten step stairway has been entirely carved in granite boulders. In all the area of Machu Picchu there are plenty of ponds and water fountains called pacchas, carved in rock or interconnected through canals and channels carved into the rock.

The major attraction of Machu Picchu may be the amazing technical level that the Inca engineers and constructors achieved, as well as the perfect fit of the granite boulders with which the walls, wooden doors and beams and straw roofs were built.

In some of the buildings, the joints between the carved rock blocks are such a close fit that it is impossible to introduce the tip of a needle in them.

Among the architectural groups of major interest there are: the so called Royal Mausoleum, located very close to the gate of the Citadel; the Sun Temple, the Tower (a circular storied structure); the Priests' House, the Three-Windowed Temple, the Main Temple, the "Sunken" Building and the fountains that form part of the Inca Liturgical Pools; as well as the aqueducts, and the stairs, all entirely made of stone. Lastly, there are rocks with a high ritual content, among which the Intihuatana or "sundial" stands out.

As a consequence of its strategic location, where safety was a prime consideration, the number of temples, its architectural quality and the quantity of kanchas (apartments for extended families), among many other characteristics of Machu Picchu, there is a generalized conviction of the fact that originally it was a center of regional power dependent on Cuzco. That is, it was a political and religious capital. It actually served as a dwelling place for the Inca or any other superior dignitary of the capital, as well as for a select aristocracy that had the privilege of having an Aqllawasi, something like a monastery for chosen women or "Virgins of the Sun", consecrated to worship, and for the service of the most privileged class.

Machu Picchu is composed of two sectors: agricultural and urban. The agricultural area is made up of terraces for cultivation. The urban area is made up of streets, flights of steps, water channels, small squares and other minor buildings. The buildings are basically of a single rectangular story. The windows and gates are of trapezoidal shape, as well as the niche where the idols or other objects were put. There are no roofs any more, due to the passage of time, since it is estimated that they were built with logs and covered with ichu (straw).