One of Gaudi’s earliest residential commissions, this private home built for the owner of a tile factory clearly references that profession, with a façade adorned with colorful tile that seems to predate pixel art by a good century. Completed before the architect developed a more organic, curved aesthetic, the home features an array of nature references and Moorish touches, such as a domed smoking corner and muqarnas. A privately-owned building normally only accessible to the public on Saint Rita's Day, May 22, Casa Vicens was purchased by a subsidiary of the Mora Banc Grup, which is currently renovating with an eye toward opening as a museum next year.

An apartment complex built for a wealthy family, the seemingly anthropomorphic Casa Mila was nicknamed “La Pedrera” (the quarry) by locals for its curved and sculpted limestone façade. And while the exterior initially made the public a little nervous when it was completed in 1912 (potential renters were unsure they’d be able to furnish such uniquely shaped rooms), its since gone on to be recognized as one of Gaudi’s late-career gems. Steel frames and a self-supporting stone façade hold the weight of this nine-story complex, which allowed Gaudi to freely experiment with curves, including an attic filled with a series of 270 varying parabolic arches. Like many Gaudi masterpieces, it was named a UNESCO World Heritage site in 1984. The complex is now a museum open to public tours.

A well-meaning attempt to turn a site on Muntanya Pelada (Bare Mountain) into a model housing development in the tradition of the English garden city movement, Park Güell was actually a flop when it debuted and was abandoned in 1914. Count Eusebi Güell, one of Gaudi's greatest patrons, had hired the architect to create a miniature city outside Barcelona, and while it tanked before the architect was able to design any of his own homes, his landscaping work has made this one of the city's most beloved parks. From a plaza and pair of gatehouses to “el drac,” a multihued salamander mosaic on the main grounds, Gaudi's public architecture on this site stands as a highlight of his more naturalistic phase. Curved benches in the shape of sea serpents and pathways which lead up to a vista with a wonderful panoramic view of Barcelona make Park Güell a must-see for any visitor. During the later part of his life, Gaudi lived in a house in the park, La Torre Rosa, for decades; visitors can tour the interior and see some of his original furniture designs.

When Gaudi became involved in this towering structure in 1883, taking over from another architect, it's unlikely he understood how devoted he would become to this project, set to become the tallest church in the world when completed (architects currently estimate the 560-foot-tall structure will be done by 2026). Gaudi spent the end of his life laboring on this towering monument, an all-consuming effort for which he effectively took a vow of poverty (when he was hit by a tram and killed in 1926, with only a quarter of the structure complete, he was dressed in such shabby clothing he was mistaken for a pauper). Gaudi’s original, towering design, filled with abstracted shapes and incredible detailing, foresaw no fewer than 18 spires gracing this complex web of stone, one each for the Apostles, evangelists, Mary and Jesus. Current architects and designers, who have sped up the long construction process by using computer-aided programs to cut the stone specified by Gaudi's blueprints, still marvel at the complex shapes he was able to formulate nearly a century ago.

One of the Gaudi's early works, this private mansion for Eusebi Güell was a high point in Catalan Art Nouveau architecture when it was finished in 1888, just in time for the Universal Exhibition that came to town that year. Guests would enter in carriages through a pair of massive wrought-iron gates, patterned in part after seaweed and horsewhips, and then proceed through a series of well-appointed room to a towering main parlor meant for entertainment, itself a parabolic pyramid forming a massive domed ceiling.

Gaudi comes from a long line of metalworkers and boilermakers, so it seems appropriate that his first major commission would be this detailed, wrought-iron gate, a reference to a mythical dragon from the legend of Hercules. Eusebi Güell commissioned the young architect to work on a series of small projects around his family’s holiday home from 1884-1887, including this gate as well as a few other small structures and landscaping. Their relationship, and Güell’s money, would support many of Gaudi's masterpieces.

Built in 1899 as a commercial and residential space for textile magnate Pere Màrtir Calvet, this Baroque building shows Gaudi at his more restrained and conservative, a straight-laced set of ironwork and columns with just a few hints of the Catalan great’s freewheeling imagination at work. Gaudi made many references to the client within the structure, such as columns shaped like the bobbins found on sewing machines.

Gaudi took over this institutional project in 1899, a rectangular building including classrooms, bedrooms for nuns, and a gorgeous wrought-iron gate.

Built between 1900-1909 on the hilltop site that formerly held a royal summer residence, Bellesguard (“beautiful view”) offers just that, a modernist stone manor house that stands as Gaudi’s version of a castle. While it’s capped with gargoyles and a red-and-gold Catalan banner, the building offers a relatively conservative, rectilinear expression of Gaudi’s style.