I will never forget the first time I saw La Sagrada Familia after coming out of the Barcelona underground. I'm not a religious person, but the building had a profound impact on me at first sight. I figured I would spend 20 minutes looking around before I got there -- I ended up spending nearly four hours exploring. In addition to the Gaudi architecture, I was really taken in by the sculptures by Josep Maria Subirachs. I highly recommend checking them both out.