Barcelona can be an awkward city to visit in my opinion. It has one of my favorite all year round weathers, it has both beach and mountains, amazing food, and the chance for great day trips. Why is it awkward then you might ask. The awkward thing is finding a reason and the will to leave each time I visit.
As soon as you arrive to the city you'll be confronted with two choices that signal that you'll be having a fun weekend. Should you get some tapas -a traditional mix of appetizer or snacks and don't let anyone tell you it can't be a full meal-, with beers or tinto de verano? In case you don't know, tinto de verano is one of the greatest inventions of humanity, an ice cold wine macerated with fruits similar to sangría, going down as easy as water but also reminding you its wine when you try to get up from the table and everything seems to shake a bit. In the end, as far as difficult choices go this is one of the best to have, as both choices work great and you won't feel sad about either of them.
After a well deserved break you can start your vacation by walking down la rambla, a pedestrian street full of businesses, local performing artists and full of trees that provides some much needed shade from the scorching summer sun as you slowly head down to the beach, most enjoyable with a second pint of tinto de verano in hand.
Barcelona's beaches can be quite crowded global pandemic or not, but if you walk along the coast you'll be sure to find at least one semi secluded spot where you can drop your towel and enjoy the sun. The sea is quite calm and perfect for refreshing yourself and swimming a bit if you're into that. All in all, you could probably spend the whole weekend just day drinking (and night, because why not) but it would be a disservice to a city that offers so much.
If you feel in the mood for some hiking you can go up montjuic, a lovely mountain from which you can get great panoramic views of all angles of the city as you work your way up. You'll pass along a lot of beautiful garden where you can take a rest and chill for a bit among the nature and appreciate the local flora. There's also the historic botanical garden to visit, which can make for an interesting little walk. Also situated here is the national place an amazing building that will satisfy some of your renacentist architectural vibes.
All in all a good afternoon plan if you're tired of the beach or just wanting a change of pace.
If you're up for more modernist stuff there's of course all of Gaudi's works laying around for you to visit. The casa Battlo, a former townhouse constructed for the Batllo family and also called the dragon house for its natural forms and tile facade.
La pedrera, which as its name suggests its a rough looking stone quarry of a building located near the Passeig de gracia.
Park guell, definitely worthy of a visit even if you don't wish to go into the closed attractions which feature some of Gaudi's innovative housing ideas. And of course La Sagrada Familia, the famous basilica and probably Gaudi's most ambitious project that has yet to be finished. Even if you don't feel like paying the entrance fee for most of these buldings I strongly recommend you pay them a visit at least, as the innovative designa are definitely worthy to take a look at.