The MACBA is the Museum of Contemporary Art of Barcelona, in El Raval, behind the University of Catalunya and the Contemporary Culture Center of Barcelona, the CCCB.
It is a very big, modern and pleasant museum, standing out for its large white facade. The museum is opened during the summer from Monday to Friday between 11 am and 8 pm and closes at midnight on Tuesdays and Thursdays. The entrance fee to the MACBA collection costs 3€, and the best part of it is that this ticket is valid for a duration of one month during which you can go in and out as many times as you want.
Perfect to spend an hour at the end of the day, relaxed, go back home without having to assimilate too much information. There are days the museum is free, you can check it on their website, like the day after the opening of an exhibition for example.