Concierge.com's insider take:
A world of spacious boulevards in a neatly beveled grid system, ostentatious houses, fine restaurants, and the city's shopping triangle—Avinguda Diagonal, Passeig de Gràcia, and Rambla Catalunya—the Eixample is as distinctly middle-class today as it was bourgeois in fin-de-siècle Barcelona. Taking its name from the Catalan word for extension, it was built to cope with the ever-swelling population at the start of the 19th century. It is the heart modernisme, the 20th-century art and design movement that juxtaposed elements of nature with skilled craftsmanship. The Eixample contains a host of remarkable buildings: The Mançana de la Discòrdia showcases three of the great modernista architects' work on one block, Casa Amatller by Puig i Cadafalch (1898); Casa Batlló by Gaudí (1904–1906); and Casa Lleó Morera by Lluís Domènech i Montaner (1902 and 1906).