The National, Deadmau5 for Open'er 2011
More names revealed for Poland festival
British indie band Two Door Cinema Club
will also perform at the festival alongside the previously announced Coldplay,
Pulp, M.I.A, Primus and Foals.
Four-day camping tickets are on sale now, priced at £85/410PLN, with day tickets and three-day packages also available.
Heineken Open'er takes place at Gdynia, Poland from 30 June to 3 July 2011.
Click here to buy Heineken Open'er tickets.