St Paul’s Cathedral has been restored to its former glory after 15 years in scaffolding.

The £40 million restoration included cleaning centuries of soot and pollution off 150,000 bricks in the cathedral’s exterior walls.

Restoration was also done on the interior, including the grand organ, and wheelchair access was added to the crypt and the Whispering and South Triforium Galleries.

The south churchyard gardens were landscaped and the American Memorial Chapel, built to commemorate US forces who died in World War II, was also cleaned and restored.

It is the first time that the cathedral has been comprehensively restored inside and out.

The painstaking project has finished in time for the 300th anniversary of the completion of Sir Christopher Wren’s masterpiece.

The Rt Rev Graeme Knowles, Dean of St Paul’s, said: “We’re thrilled that in the year we celebrate the anniversary, we can mark the completion of this extraordinary project.

“The two million who come here each year can witness Wren’s original vision.”

Martin Stancliffe, Surveyor to the Fabric, who oversaw the project, said: “This great building is now in a sound state and probably looks better than at any time since its completion in 1711.”

The cathedral’s 300th anniversary will be marked at a special service on Tuesday.

Photographers are being invited to submit their best shots of the cathedral’s exterior in a competition taking place as part of the celebrations.

Photographers can enter the competition by uploading their photos to Flickr: www.flickr.com/groups/stpaulslondon/