Farther up Passeig de Gràcia is Casa Milà, designed by Gaudí and built in the early 20th century (finished in 1912). The people of Barcelona were so shocked by its unique design that they named it La Pedrera, Spanish for “the quarry.”
Gaudí supposedly designed the building for maximum interaction–there are elevators only on every other floor, necessitating neighborly love (and exercise).
One floor of the building is staged as if inhabited by a family from the time it was originally in use.
The otherworldly structures on the roof, some of which are chimneys, recall several things both from science and science fiction: the vertiginous columnar cities that crop up around active hydrothermal vents in the deep sea, as well as stormtroopers.
This one reminded me of Sam the Eagle:
Casa Milà, Barcelona, September 2010