Councillor Dave Trimble, Nottingham City Council Portfolio Holder for Leisure, Culture and Tourism, says the planned development of Nottingham Castle will create jobs and boost tourism to the city.
Plans to develop Nottingham Castle as a world class heritage attraction are being stepped up.
The Castle Working Group says it is disappointed the castle was not selected for this year's Heritage Lottery funding but it is planning to resubmit for the next round.
The grant of £15 million would be part of an overall cost of £26 million to develop the Castle.
Plans include a new "Robin and the Rebels" discovery centre, telling the story of the legend of Robin Hood.
Erin Huckle from Experience Nottingham says a revitalised Nottingham Castle will mean tourists will stay for longer in the city.