This may be the most unique of the many works which Eusebi Güell entrusted to Gaudí. It was declared a universal monument by UNESCO in 1984, along with two more works by the brilliant architect. Considering this, we may gain an idea of the beauty of this work.

Güell originally wanted his property to become a "garden-city," like those which were built in England, for the rich bourgeois of Barcelona. He divided the land into 60 plots between 1000 and 2000 square meters in size, and triangular to adapt to the topography of the land. When somebody purchased a plot they had to sign a contract accepting conditions including an absolute prohibition on the felling of trees, a limitation of the size of the house to 1/6 of the total surface of the plot, and a maximum fence height of 80 centimeters. Only three plots were sold: two for the home of the Trias family, which they still own, and another to build the show-home, which Gaudí ended up buying in 1906, and which is now a museum dedicated to the park's architect.

Güell Park, the construction of which was commenced in 1900, occupies two properties: Can Muntaner de Dalt and Can Coll i Pujol, on Muntanya Pelada (Bald Mountain), in the Barcelona neighborhood of Gràcia. The mountain really deserved its name, because its vegetation was scarce: only simple grasses, bushes and a few carob trees. Gaudí wanted to cooperate with nature, so he ordered the creation of an autochthonous natural area based on Mediterranean species, which are stronger, but require less water and maintenance.

He did not only respect the atmosphere by planting trees. When a topographic map was made of the fifteen hectares which Güell had purchased, Gaudí observed that, given the characteristics of the land, many leveling and embankments-which would ruin the beauty of the land-would be necessary to build roads, so he designed the famous viaducts which allowed the mountain's natural shape to be preserved. These viaducts are supported by inclined columns, with manufactured brick centers, covered with natural stone from the site. There is a total of three kilometers of roads, with grades from 6% for cars up to 12% for pedestrians.

The park is surrounded by a rubblework wall, which is crowned by the undulations of ceramic "trencadís" (a type of mosaic made from broken pieces of tile) and seven gates. On the main gate, located on the Carrer d'Olot, large circular medallions with the words "Park" and "Güell" written with "trencadís" mosaic notify us that this is where the park begins. The grilles for this door came from repairs performed on the Casa Vicens in 1965; they were placed to substitute the original wooden door. At each side of the entrance we find two pavilions which remind us of the gingerbread house from the famous tale of Hansel and Gretel, by the Grimm Brothers. These pavilions, built between 1901 and 1902, have an egg-shaped form with the complete absence of straight lines or angles, and their structure is based on wrought reinforced ceramic beams and brick vaults supported by weight-holding walls.