Built between 1886 and 1890, this Antoni Gaudí masterpiece has all the telltale touches of genius expected of Barcelona's famous architect. Commissioned by wealthy industrialist, politician, and patron of the arts Eusebi Güell. Named a UNESCO World Heritage site in 1984 (Gaudí is responsible for seven awarded sites!), the palace is less well-known compared to other Gaudí locations in Barcelona like Park Güell and Casa Mila.