Work on an £11.6m history centre in Chippenham has been completed, with the building due to open next October.
The centre will have seven miles of shelving for documents charting the history of Wiltshire and Swindon over the last seven centuries.
This archive is currently held at the Record Office in Trowbridge.
Access to the new centre in Chippenham will be improved through larger reading rooms and better internet facilities, Wiltshire County Council said.
An education room for schools will also be provided.