Hi all - would appreciate your thoughts. We will be arriving in Barcelona the morning of July 8 and will be staying for 3 nights. The sites we don't want to miss are Sagrada Familia, Picasso Museum, La Pedrera, Park Guell, Palace of Catalan Music and Palau Guell. Of course, we will be exploring on foot, as well. On all of our journeys, we always purchase tickets ahead of time to avoid long ticket lines. Regarding the above sites, are there any that you recommend we purchase online more than several days in advance to avoid the possibility that the online tickets sell out during the days we will be in Barcelona? I'm uncertain as to whether any of these sites actually "sell out" via online purchase or if there is always the ability to purchase for a particular timeslot on any given day. For our later trip to the Alhambra, it was made clear to us that the tickets actually do sell out, and usually months in advance, so we already bought those.
I already bounced this question off of TA Barcelona advisor Enric, who was very helpful but thought I'd get a few more thoughts from you all.