In Madrid and Barcelona which tkts are a pre-purchase MUST? I want to use my short time in these cities wisely and would rather not stand in lines. Thank you in advance for your expert advice.
Only one is really Sagrada Familia. When are you going and what are you wanting to do?
Buy the RS Barcelona book. He explains the 8-10 attractions that REQUIRE pre-purchasing tickets. And gives you plenty of other information about what you might want to do in a "short time" (whatever that means).
If you want to see a bunch of the most popular sights in Barcelona in a short time, it would be a mistake to arrive in the city having only pre-purchased the La Sagrada Familia ticket. You really need to have your ticket in hand when you arrive at a lot of places to avoid spending a long time (as in an hour or more) standing in a ticket line, and possibly not even getting into that day. These other sights are also a problem:
- Parc Guell: You can no longer buy a ticket at the park, and before they implemented that policy, the lines were often quite long.
- Casa Batllo: Ticket lines are long.
- Casa Mila: Ticket lines are long.
- Picasso Museum: Ticket lines are long.
- Palau de la Musica Catalana: English-language tours can sell out
- Camp Nou Experience: A soccer-related thing that sells out really early.
That list is not intended as an indication that you must go to all those places. It's just that many people want to go to a lot of them, thus the lines--not to mention the severe crowding at the Gaudi spots and the Picasso Museum.
Madrid isn't as overwhelmed with tourists as Barcelona is. While I didn't run into bothersome lines in 2016 (five years ago), some folks have recommended pre-purchasing a ticket to the Palacio Real, and a few have even suggested doing that for the Prado Museum. it's clear that the experience varies. It's my impression that a considerable amount of the traffic at those two places is Spanish, and possibly local, so I think lines may be shorter on weekdays as opposed to weekends. In any case, I wouldn't panic about buying those tickets early. If you're trying to visit during a free period (warning: they could be more crowded then) and there's a way to get a ticket ahead of time, that would be a smart thing to do.