Islamic Interpretation of Dreams (Ibn-i Sirin):

(Auditorium; Large hall) A large hall in a dream means comfort, overcoming financial difficulties, a helping wife, a good mistress of the house, a high ranking position that involves little danger, a highway sign, a praiseworthy son, a hard working employee, or a good investment.

Ifthe hall is dark, dirty and filled with insects and spider webs in the dream, then it means the opposite.