The Crypt of the Church of Colonia Güell (1898-1914) Colonia Güell was a small workers' village, which was built in 1882, next to Mr. Güell's textile factory located near the town of Santa Coloma de Cervelló, in the Baix Llobregat region, about 20 km. from Barcelona. The Colonia occupied about 30 of the 160 hectares on the "Can Soler de la Torre" estate, which Güell's father had acquired in 1860. The workers' homes were spread around the factory in a regular pattern, with small two-story houses, built by Gaudí's assistants, Francesc Berenguer i Mestres and Joan Rubió i Bellver.

Güell, the future Count, planned for all kinds of services to be available to his factory employees, including a church. Gaudí was put in charge of building it, and he enjoyed the opportunity to work on a project from the beginning, not being limited to a predefined floor plan as had been the case with the Sagrada Familia and the Col.legi Teresia.

Gaudí spent ten years working on studies for the design, and developing a new method of structural calculation based on a stereostatic model built with cords and small sacks of pellets. The outline of the church was traced on a wooden board (1:10 scale), which was then placed on the ceiling of a small house next to the work site. Cords were hung from the points where columns were to be placed. Small sacks filled with pellets, weighing one ten-thousandth part of the weight the arches would have to support, were hung from each catenaric arch formed by the cords. Photographs were taken of the resulting model from various angles, and the exact shape of the church's structure was obtained by turning them upside-down. Gaudí took photographs from various angles so he could see vertical sections or elevations of the building.

Gaudí's design was to be a crypt with a portico, taking advantage of the unevenness of the land, and a four-floor high chapel which would be reached via a stairway above the portico. The church, located on a small hill, would have blended with the pines because of the color scheme that Gaudí had designed: the crypt walls are built with arch bricks and black basalt, representing the earth and the tree trunks. Further up the walls, the material was intended to gradually change to green hues, like the tops of the trees, then blue, like the sky, finishing white and golden at the highest part of the bell towers, representing the clouds in the sky and the sun. At the same time, this chromatic process is a symbol of the path to Christian living, from the shadows of hell to the light of the Glory of God.

Work did not begin until late 1908, and just when the crypt was being finished and construction of the chapel walls was beginning, work was stopped because of the death of Count Güell, in 1914. The model remained intact in the workers' shed, along with the photographs and plans, until they were burned and destroyed in 1936, at the outbreak of the Spanish Civil War.