The Palau Güell was designed by the young Gaudí and is a wonderful blend of medieval opulence and the architect's unique exuberant style. Completed in 1890, the building was the private residence of Gaudí's patron, Count Güell. The Palau Güell is a designated UNESCO World Heritage Site.

The wealthy industrialist, landowner and politician Eusebi Güell i Bacigalupi (Barcelona, 1846-1918) was Gaudí's main patron. In 1885, when the architect was still unknown, Count Güell commissioned him to design his private residence. Gaudí was aware that Güell wanted to show off his wealth to his friends and acquaintances (the house was to be used for exhibitions, concerts and other events) and he created an unusual, bold architectural project. He made innovative use of traditional building techniques, as well a wide variety of materials, with particular emphasis on more expensive ones such as marble. Gaudí combined the typical square structure of Catalan medieval palazzos and exquisite wooden coffered ceilings with innovations such as the parabolic arch which became a hallmark of his work. However, Gaudí didn't just create a palazzo, he created a metaphor too, as the building rises up, like Güell, from poor beginnings, represented by the austerity of the basement and ground floor, to wealth, as embodied by the riot of colour on the roof. Indeed, the ground floor, with its simple grey marble, contrasts magically with the interplay of colours and forms of the 20 sculptural chimneys on the roof. The architect covered the chimneys in waste materials, including broken tiles and plates from the Cartuja de Sevilla pottery. A mosaic of ceramic tile, marble and stained glass that becomes the iconic symbol of the Palau Güell.