I thought someone on this thread mentioned seeing Sagrada Familia in 90 minutes. We just visited Sagrada Familia a few days ago. I think it is safe to say that 90 minutes doesn't begin to do it justice. There is so much at which to marvel, both inside and out. Imho, it could easily be designated the 8th wonder of the world. Definitely not to be missed, even if it means going back independently on your own. Most tours have some built in "free" time for exploring on your own. You can easily get there by Metro, cab, or the Hop on Hop off bus, which stops for a generous few minutes literally in front of the Passion Facade, and provides great photo ops not possible from within the ticketed area. Definitely buy your tickets ahead of time from the Sagrada's own official website. If you're 65 or over, reduced tickets are available, officially it states that they reserve the right to check for proof of eligibility, but when we checked in they said they didn't need to see proof (our passports) that day.