Residents in Firhouse say they don't know what the new building will be used for.
Protesters are gathering outside The Church of Scientology's massive new centre in Dublin today.
The leader of the secretive religion - David Miscavige - is expected to attend the opening ceremony at the centre in Firhouse - which can seat over a thousand people.
Demonstrators from Ireland and abroad have been arriving outside - many of them former members of the church which they say is a 'cult'.
Bill and his mate - who’ve come over from Plymouth - have brought “one thousand Xenu balloons” with them for the day. pic.twitter.com/RQ3Sqjr3N6— Richard Chambers🎙 (@newschambers) October 14, 2017