You might consider a day trip to Montserrat.
You can buy a pass (if they still sell them) that covers subway fare to the train stations , train to the base of the mountain, and either the funicular or the cable car up the mountain.
Last time we were in Barcelona we purchased this combo ticket from the small rail office in the retail area of Plaza Catalunya.
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+1 on taking subway to train, then funicular up the mountain, a DIY type of tour. Opt for the lunch included with wine fountains
It is not obvious where the included lunch is actually held when up there.
As for hotel we stayed here for 10 days.
Loved the location as close to some things, and great bus service around the corner (buy tickets at smoke shop) Could go everywhere by bus.
Website for hotel is poor, but google it on tripadvisor. Rooms are not large, ours had a balcony which is small but usable. It's not fancy at all, but not expensive and is clean.
https://www.medicishotel.com/en/
Barcelona is wonderful. Easily even a week’s worth of things to do, 2 days will barely scratch the surface plus you have to recover from jet lag. Wonderful seafood eateries as well.
Tons of places to stay - you might think of which part you want easy access to.
You know, we’ve been all over Spain, and the food is just outstanding. I don’t understand why the Spanish aren’t as famous as the Italians or French for their wonderful regional foods. And for Spain, Barcelona even stands out, ha ha.We stayed at the modern Ocean Drive hotel in Barcelona this past May, https://od-barcelona.topbarcelonahotels.com/en/. We very much enjoyed the breakfast buffet (I think I need to go back for more Spanish chorizo) and the rooftop bar. The friends we were with had previously stayed there as part of their Vantage Douro River cruise package.
Staying a week in the Gothic District this year, used the subways to get around, great food. Get tickets to Sagrada Famila early, they often sell out. Took a private ($) tour to Monserrat was worth it as we arrived an hour before tour busses. Other Gaudi places are worth seeing
And don't forget to raise a toast to my favorite Barcelona émigré.
Barcelona is far larger than I expected it to be. A great way to get an overview is to do the full-city Grayline open top bus tour, which is narrated and which allows for hopping on and off at all the major sites. It’s touristy but totally works.
Surprise #2: Any Spanish you may speak is useless. They speak Catalan