Marvel is getting set to destroy the box office competition once again with the May 1 release of the highly-anticipated Avengers: Age of Ultron. Entertainment news programs Access Hollywood and Extra both got to visit the set in London last year, revealing new behind-the-scenes videos. Access Hollywood's piece gives us a few brief glimpses inside Avengers Tower, the new headquarters for Earth's Mightiest Heroes. Mark Ruffalo and Jeremy Renner also take us inside the Quinjet set while Robert Downey Jr. and Chris Hemsworth tease "upgrades" to their costumes.

Extra's video gives us a quick glimpse inside Bruce Banner's (Mark Ruffalo) laboratory, although it is after the Hulk made his presence known, since the lab is highly damaged. Chris Hemsworth and Chris Evans also reveal that they're glad they aren't writer-director Joss Whedon, since he has the unenviable task of trying to top 2012's Marvel's The Avengers. Robert Downey Jr. also adds that Jeremy Renner's Hawkeye is "much more central" to the plot, and that his co-star is the only one Joss Whedon "gets excited about doing stunts."

When Tony Stark tries to jumpstart a dormant peacekeeping program, things go awry and Earth's Mightiest Heroes, including Iron Man, Captain America, Thor, The Incredible Hulk, Black Widow and Hawkeye, are put to the ultimate test as the fate of the planet hangs in the balance. As the villainous Ultron emerges, it is up to the Avengers to stop him from enacting his terrible plans, and soon uneasy alliances and unexpected action pave the way for an epic and unique global adventure. Take a look at these behind-the-scenes videos below, and stay tuned for more on Avengers: Age of Ultron, arriving in theaters May 1.

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