Machu Picchu and the Intihuatana stone, Golden Rectangle

Successive Golden Rectangles dividing a Golden Rectangle into squares (Machu Picchu and the Intihuatana stone).

Machu Picchu. Built in the 1460s and abandoned for three centuries after the Spanish conquest, Machu Picchu, or “Old Peak” in the Quechua language, was rediscovered by U.S. archeologist Hiram Bingham in 1911. Machu Picchu is wonderful and incomparable, not only for its unique architecture. The natural beauty is astounding.

The Intihuatana stone is one of many ritual stones in South America. The Spanish did not find Machu Picchu so the Intihuatana Stone was not destroyed as many other ritual stones in Peru were. These stones are arranged to point directly at the sun during the winter solstice. Intihuatana also is called "The Hitching Point of the Sun" because it was believed to hold the sun in its place along its annual path in the sky. At midday on March 21 and September 21, the equinoxes, the sun stands almost above the pillar—casting no shadow at all.

A golden rectangle is a rectangle whose side lengths are in the golden ratio, one-to-phi, that is, approximately 1:1.618. A distinctive feature of this shape is that when a square section is removed, the remainder is another golden rectangle, that is, with the same proportions as the first. Square removal can be repeated infinitely, which leads to an approximation of the golden or Fibonacci spiral.

Fibonacci numbers (0,1,1,2,3,5,8,13,21,34...) are a sequence of numbers named after Leonardo of Pisa, known as Fibonacci. The first number of the sequence is 0, the second number is 1, and each subsequent number is equal to the sum of the previous two numbers of the sequence itself.