We will be in Barcelona from August 18-23, so 4 full days, not counting travel days. Of course, we are interested in Gaudi and loooking at all our options within our timeframe. We want to visit Sagrada Familia, Park Guell, Casa Mila and Casa Battlo (one or both). I liked Enric's suggestion of doing Park Guell (AM) and Sagrada Familia (PM) in one day, and then perhaps do a combo ticket to Casa Mila and Casa Battlo or if we were to choose one, which one?
My other consideration is to do a bundle tour of Sagrada Familia and Gaudi houses tour like: https://www.getyourguide.com/barcelona-l45/barcelona-sagrada-familia-and-gaudi-houses-tour-t428355/ and then do Park Guell on a different day.
I would appreciate any thoughts or other suggestions! We want to explore other parts of Barcelona as well.