Machu Picchu is considered a masterpiece of architecture and engineering. In fact, hardly was discovered and first studied in the early decades of the twentieth century, the world hailed it as wonderful and as researchers are delving more about its structure, even more amazing is the achievement of architects and engineers Incas who created it in the 15th century.

Scrupulously planned to build a citadel on the heights of a remote mountain jungle would be a challenge even for engineers today, but the Incas did without the help of the wheel and iron. And while it is true that Machu Picchu has really beautiful architecture, its real charm lies in its general design in harmony and balance between each element of this majestic and functional refuge.

All buildings of the citadel faithful to the classic Inca architectural style, which is characterized by its walls of polished stones with perfect joints between them, its trapezoidal openings and ornamental niches, among other things. The precision with which the stones of the main buildings were carved makes it perfectly fit so that between them is impossible to introduce the tip of a needle.

In addition, the architects took into account certain rituals and astronomical criteria for the construction of the main buildings. Some of them coincide with the solar azimuth during the solstices, with points of ortho and solar sunset at certain times of the year. The Incas also designed their spaces to take advantage of the sight and sound of water flowing through the Urubamba River and pools.

The challenge of building a city of stone on top of steep mountains in a region bathed by heavy rains, subject to frequent earthquakes and almost inaccessible, forced the Inca engineers to develop a sophisticated strategy for the construction of Machu Picchu. And the fact that the buildings are still in good condition despite suffering centuries of neglect, demonstrates how successful their solution was. Today, researchers say that the drainage system of the citadel was the key to his longevity. This system is engineering works that lie hidden beneath the ruins which concentrated 60% of efforts the construction of the citadel. This orderly and well planned drainage system also guaranteed the purity of the water, showing that the Incas were concerned about good hygiene, centuries before Europeans.