The cathedral is a World Heritage Site
A five-year fundraising campaign has been launched to raise £7m to boost facilities at Durham Cathedral.
The World Heritage Site wants to improve access for the 600,000 people who visit every year.
Church officials also plan to develop the cathedral's collection of artefacts and manuscripts and expand its links with schools and colleges.
Cash is also needed to repair the cathedral fabric, most of which dates back to the 12th and 13th Centuries.
The Dean, the Very Reverend Michael Sadgrove said: "Durham Cathedral has been a familiar and much-loved icon of north-east England for more than 900 years.
"Although the world has changed vastly since then, the cathedral still has much to contribute to public life through its matchless heritage, programme of arts and education opportunities for children and young people.
"Our development programme captures what we believe will be central to our mission as this new century unfolds and will help us to ensure that we can broaden the scope of our ministry to people far and near.
"We want to do this with the support and collaboration of individuals and organisations across the city, county and region, and indeed beyond."