Although this square is a bit hidden, it's worth looking for because of its mysterious atmosphere and the Baroque church standing there. There is a school next to the church where 42 people died in 1938 during a bombing raid by fascist planes. See the plaque commemorating their lives.
More information at Visit Barcelona http://www.barcelonaturisme.com/wv3/en/page/1247/placa-sant-felip-neri.html
Address Plaça de Sant Felip Neri, 08002 Barcelona, Spain
Coordinates 41°23'0.161" N 2°10'30.298" E