A new multi-million pound public archive centre is being proposed for East Sussex.
Some of the records at The Maltings date back to the 11th Century
The county council was told its current building at The Maltings in Lewes was inadequate after a National Archives Inspection in 2006.
The authority has earmarked two possible sites for a replacement, which will be called The Keep and could cost up to £22m to build.
Some of the documents at The Maltings are more than 900 years old.
Brighton and Hove City Council has joined the project board and will look at the possibility of moving some of its museum and libraries collection to the building if the plans go ahead.
The county council is expected to make a bid for lottery funding later in the year.
East Sussex councillor Bob Tidy said: "We have narrowed down our search for potential sites and have agreed to choose one of two sites identified near the universities in Brighton.
"The project is dependent upon gaining lottery funding and partnership help if it is to become a reality.
"But if we are successful with the finances and planning we could have a brand new historical resource centre up and running and serving people in the area by 2011."
The current record office at The Maltings in Lewes has been in operation since 1949.