Casa Batlló or Casa Milà in Barcelona and Food Market

Loved my visit to Casa Batllo back in 2015. We were given an audio device that was great at describing the work and his vision throughout the house. His Art inspiration for this house was all about the sea. Woodwork staircase is just gorgeous.

I think you and the family would enjoy this casa very much. Whether you have time for it can only be answered by you. You will need at least 1.5-2 hours to do it justice. If you are looking to squeeze it in on the same day as La Sagrada Familia and Park Guell, I think it would be too much in one day.

Edited to add: I went to both markets in Barcelona and Madrid and would say my experience was better at the one in Madrid because it wasn’t as crowded as Barcelona and I guess the weather played a part too because it was a rainy day in Barcelona when I visited the market.

The two places are very different, so I think you should just pick the one that aesthetically hits your sweet spot. Casa Batllo is pretty awesome peak Gaudi. I can't imagine anyone thinking it wasn't impressive. As far as crowds go, I can't comment because I did a nighttime concert package. As an aside, that's a great way to see the place and experience a bit of music. If it were me, I'd bag Park Guell entirely. Sagrada Famila is a stone's throw from the awesome and less trampled Hospital Saint Pau. I'd combine those two places in a heartbeat. Alternatively, investigate a guided tour of the Palau de la Musica Catalania. That is mind-flowingly awesome. If you're a Gaudi geek, and you're in the Gracia area, Casa Vicens is pretty neat. That was early Gaudi so it's an interesting bookend to his later stuff.

Can't comment on Mercado San Miguel. Triana is a lot more low key than La Boqueria. It's still touristic but less so. If your goal is a real daily market experience, neither is really a good bet. I'd chose Boqueria if you don't mind a big tourist market vibe.

I’ve been to Casa Batlló twice. The first time to Casa Batlló was during the day and while the building is gorgeous, I hated how crowded it was. A couple of years later when I was in Barcelona again, I happened to be walking past it during the evening - maybe 7, 8pm. It was November so it was dark. On an impulse I went in again. It was so much less crowded and on a dark night it was simply magical. The rooftop, particularly. So I do recommend that as an option, if it’s offering late hours.

I do think his domestic architecture adds context, and honestly of the sites, Parc Guell is my least favourite and the most time-consuming to get to in a short trip.

For something different and non-Gaudi but in the same vein, book a tour of the Palau de la Musica Catalana, which is extraordinary and helps put Gaudi in the context of his peers. Or simply wander around the Recinte Modernista de Sant Pau, which is a short walk from Sagrada Familia. Both of these are the work of Gaudi’s contemporary Domenech i Montaner.

Just realised I’ve said pretty much the same as Chris above!

Casa Battlo’s marine theme is everywhere in Gaudi’s remodel of the mansion. In one part of the mansion, a passageway looks like you’re experiencing Jonah’s journey into the belly of a whale. As you climb the Casa’s interior staircase, be sure to look through the textured clear glass enclosing the staircase. Through the glass, the square colored tiles on the masonry walls beyond change shape and look all kinds of colorful fish 🐠 as though you’re viewing them in their underwater world.

Casa Battlo is an incredible place.

I enjoyed my visit to Casa Mila in 2019. Not only is the architecture amazing but I enjoyed touring the apartment as I enjoy touring old homes and seeing how people lived in the past. I also visited La Sagrada Familia and Park Guell so feel it was a nice mix. I did not have time to tour Casa Batllo but enjoyed walking past the exterior in the evening. You can’t go wrong with either.
I preferred Mercado de San Miguel in Madrid, I had a wonderful lunch there.