The trustees of East Bedlington Community Centre raised the funds to ensure the landmark building on Station Street in Bedlington Station is retained for community use for decades to come.
It offers activities over three floors and also contains a licensed community café. The original dance hall floor dating back to 1886 has been recovered and a state-of-the-art sound and light system has been installed.
Other attractions for local organisations include a light and spacious activity room and a meeting room.
In a unique partnership with East Bedlington Parish Council, the centre trustees have been able to enter into a long-term lease with property owners Sleekburn Estates and create a fully accessible community building.
The parish council has contributed £450,000 towards the capital scheme, which also received £845,715 from Big Lottery Reaching Communities (Buildings) and £48,500 from the Coal Industry Social Welfare Organisation.
The Duchess said: “It is particularly pleasing to see that the integrity of this fine building has been retained and the contemporary twist has paid tribute to the rich industrial heritage of the former Bedlington Engine & Ironworks.
“The scheme is an excellent example of organisations working together to deliver real benefits to the community and it is a privilege to officially open this facility.”
Refurbishment work has been carried out by Brims Construction Ltd under the instruction of a design team that includes Hugh Massey Architects, Taylor Design, Artis Consulting and BDN structures.
The centre will fully open for bookings from Monday. For more information, call 01670 828808.
Chairman of the board of trustees, Ron Straughan, said: “It has been quite a journey for us and we are very pleased that Her Grace has been able to officially open the centre.
“We cannot wait to start providing activities, including youth clubs, for residents and visitors from outside the area.”