La Mercè Festival Barcelona 2016 La Mercè 2016 - Top Events Merce Festival Barcelona. English guide to highlights of Barcelona's biggest festival. Mercè is also called Les Festes de la Mercè - Fiestas de la Mercè 2016. Mercè Guide, Mercè programme, maps and Top Events Mercè 2016.Merce Festival Barcelona is Barcelona's biggest festival of the year. The Barcelona Mercè festival 2016 dates areThursday 22nd September to Sunday 25th September 2016. This Mercè Festival 2016 guide in English lists the best things to do and what to see during Barcelona's biggest annual festival. The Mercè 2016 public holiday is on 24th September 2016. Barcelona's metro trains will be open all night during the Mercè festival. La Mercè is "La festa major de Barcelona" and is the biggest city festival of the year in Barcelona. Scroll down this page to find top things to do at Barcelona Mercè Festival including concerts, fireruns, fireworks, human towers and much more.