The project is designed to transform how visitors enjoy the Cathedral and gain inspiration from it.
The 'Open Treasure' exhbition will open up access to previously hidden spaces as well as show off the cathedral's collections and Claustral buildings.
It will feature artefacts dating from the third century, including burial stones, preaching crosses and medieval manuscripts.
Some of the items on show have never been publically displayed before.
Visitors begin their trip in the Monks' Dormitory and continue through a new state-of-the-art Collections Gallery into the Great Kitchen.
Next there is an opportunity to see the Cloister via the Pilgrimage and Community Galleries in the Covey.
New exhibition spaces are also allowing the Cathedral to show case more of the treasures in its internationally important collection with a rolling exhibition programme.
A new programme for learning is also being developed to provide a range of opportunities and events for school children, families and community groups.
Is it hoped that the investment will boost visitor numbers and revenue which will help pay for the conservation of the Cathedral and its collections, and ensure access to the Cathedral Church remains free.
Andrew Tremlett, the new dean of Durham Cathedral, told The Guardian: "It has been an incredibly complex project, and I am in awe and wonder of the splendours of this space.
"This is a seminal moment in the life of the cathedral."
He added that the the exhibition tells a story capturing "the history and culture which has shaped the north-east of England."
