One of Antoni Gaudi's most famous and often-repeated phrases was, 'originality is returning to the origin.' For Gaudi, a deeply religious man, this origin was nature. Gaudi viewed the natural world as perfect, a creation from which he drew inspiration. Nowhere is this connection more clearly visible than in his masterpiece, Barcelona's Sagrada Familia.

The Sagrada Familia represents the culmination of Gaudi's career. He used his other works as testing grounds for structures and techniques that would eventually be implemented in the Sagrada Familia. The elements found in Gaudi's nature-inspired work, which is sometimes referred to as biomimetic architecture, can be classified as ornamental or structural. Structural elements inspired by nature include: catenary arches, spiral stairways, conoid-shaped roofs, and a new type of tree-inspired column that uses hyperbolic paraboloids as its base. Natural ornamental elements include: honeycomb gates, vine-inspired frieze, diatom-shaped windows, gargoyles depicting animals displaced by the church's construction, and pinnacles in the form of grasses and pyrite crystals.

Both during Gaudi's lifetime and following his death, his work was considered to be revolutionary. Unlike most architects, Gaudi did not spend his time drawing plans in two dimensions. He worked with clay, rock, rope, paper, and any other moldable medium available. He expressed his plans and intentions through models and used live plants, animals, and humans as references. Gaudi did not view himself as revolutionary – he simply sought to replicate the perfection he saw in nature.

Some of Gaudi's most interesting structural techniques were successful in speeding construction and consuming fewer raw materials. The roof he designed for the architectural school on the grounds of the Sagrada Familia is shaped similar to a Magnolia leaf, in the form of a conoid. This naturally-occurring wave shape channels rainwater off the roof and was able to be made thinner, requiring less material, due to its innate strength. His tree-inspired columns could also have a smaller diameter due to the load-bearing capability designed into their multi-faced forms. Adrian Bejan has described Gaudi and this phenomenon describing him as:

A tightrope walker on the line of bridging art and science. He understood that nature is constructed by laws of mathematics. What is strongest is inherently lightest and most efficient.

By Kaitlin Yarnall and Fernando G. Baptista - Deputy Art Director and Senior Graphics Editor at the National Geographic magazine. This project is further explored here and in the December issue of National Geographic magazine.