Published: 14:30, 17 June 2014
Dover Castle is being used to film scenes for a new Avengers movie starring a host of Hollywood A-listers.
Actors Scarlett Johansson, Robert Downey Jr and Samuel L Jackson are among those filming the big-budget superhero film.
Passer-by Kimberley Ferris was able to get a picture of 49-year-old Downey Jr stepping off a helicopter near the castle.
She said: "He seemed to love our three-year-old daughter, came close to wave at her and posed, so we were quite lucky."
Film-makers Marvel Studios are using the castle, with some areas of the site closed to the public until Tuesday, June 24.
Yesterday, a KentOnline photographer captured pictures of the film rigs at the Connaught Barracks.
A private helicopter was spotted landing at nearby Broadlees Farm yesterday and is believed to be involved with the film.
An English Heritage spokesman told KentOnline: "Due to a private special event, the second floor and roof of the Great Tower at Dover Castle is inaccessible between June 9 and June 24.
"Visitors are able to experience the ground floor and first floor of the Great Tower and the rest of the 80-acre site including the Secret Wartime Tunnels as usual.
"However, between June 16 and 18, the whole of the Great Tower is inaccessible.
"Tours of parts of the site not normally open to the public are available between June 16 and 18."
Avengers: Age of Ultron is the sequel to the 2012 blockbuster Avengers film.
Scarlett Johansson stars as Natasha Romanoff/Black Widow and Robert Downey Jnr, who filmed part of the Sherlock Holmes film in Chatham, plays Tony Stark/Iron Man.
It's Johansson's second time in Dover, after she filmed the 2008 movie The Other Boleyn Girl at the same venue.
Her latest big screen outing is based on the Marvel Comics superhero team the Avengers and due to be released next year.
Last September, Hollywood star Johnny Depp reportedly stayed at a small hotel near Dover while filming Disney Film Into The Woods at Dover Castle.
The historic venue was turned into a film set for the Disney movie, which is based on the musical by Stephen Sondheim and the book by James Lapine.
Depp played the wolf in the film, which also starred Anna Kendrick, Chris Pine, Emily Blunt, Meryl Streep and comedian James Corden.
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