30,000 to turn out for event
While strict security will see delays and queues as gatherers are screened going into the event area on College Green, organisers are confident that enough time is being allowed between when gates open at 2pm and when Mr Obama speaks at 5pm.
Guests arriving for the free event are being told not to bring food or beverages and that there will be no access to shops from the site once people go through security screening.