It marks 10 years this month since the A-listers who make up the Avengers transformed a Norwich art gallery into their headquarters. 

The action blockbuster The Avengers: Age of Ultron began filming in 2014 and Marvel chose the Sainsbury Centre as the backdrop for the superhero gang's upstate New York base. 

Chris Evans, Robert Downey Junior and Chris Hemsworth can be seen walking down the corridor of the Crescent Wing offices, while Scarlett Johansson appears in a later scene in the building, which is on the University of East Anglia's campus. 

Lee Heath played the crucial part of opening the hydraulic doors for the heroes (Image: Kate Wolstenholme)

Lee Heath, head of security at the Sainsbury Centre, was a gallery assistant at the time and was responsible for opening the hydraulic doors for the stars.

“It was only about the day before that they made it known to staff it was the Avengers," he said.

"I had to lay on the floor, hiding, as the actors approached, so it looked like it automatically opened.

"They built screens around the place but people soon got a message out that something strange was happening at the Sainsbury Centre and we had to deny it.

“Closing the museum for three days was quite a challenge, to find a storyline which people would believe.

"But word gets out, there must have been 700 people there on the filming days.

Chris Evans, Robert Downey Junior and Chris Hemsworth walked through the Crescent Wing in the scene (Image: Kate Wolstenholme)

"Some of the actors actually flew in by helicopter just before they were due on their scene.

“It was a once-in-a-lifetime event.”

The footage shot 10 years ago has since been used in other Avengers films and Marvel releases such as Spiderman: Homecoming and Ant-Man.

Kat Downes, who looks after filming at the university, added: "People seen running back and forth outside Avengers HQ are our staff and students running across the top of the iconic Crescent Wing.

"It was a very exciting day."