The section of the 12th-century wall will also be on view to the public and tourists from a glazed platform where they can watch an audio-visual presentation about Viking Dublin.
Dublin City Council is planning a week-long festival to mark the opening of the new conference suite, which is expected to be ready by next summer. The festival will celebrate the Viking and medieval heritage of the city.
Deputy Heritage officer Charles Duggan says the idea for the new suite and displays arose from a 2004 conservation plan for the city walls.
"Very little of the old city wall survives and the fact that a piece of it is still intact under Wood Quay is quite a miracle."
He explains that there was an empty void under the council offices and it was seen as "a brilliant opportunity to create a civic space".
The new centre, on the lower ground floor and basement of one of the council blocks at Wood Quay, will be able to seat 120 people and will include meeting and training rooms.
It will be available at a reasonable fee to all kinds of groups and the income generated will be used for the upkeep and management of the facility.