Originally, Marvel planned to show us a Wakandan mine that produces Vibranium in Avengers: Age of Ultron but the studio nixed it, saving the first look at Black Panther's homeland for Captain America: Civil War or his 2018 solo film. Below, you can see two unused designs for the mine.
In our gallery at the bottom of the page, you can also see Thompson's concept art for the interior of Tony Stark's laboratory and Quinjet hangar in Avengers Tower, a weapon storage facility, interior of the Avengers' new upstate New York base and S.H.I.E.L.D.'s Helicarrier Lifeboats.
When Tony Stark (Robert Downey Jr.) jump-starts a dormant peacekeeping program, things go terribly awry, forcing him, Thor (Chris Hemsworth), the Incredible Hulk (Mark Ruffalo) and the rest of the Avengers to reassemble. As the fate of Earth hangs in the balance, the team is put to the ultimate test as they battle Ultron, a technological terror hell-bent on human extinction. Along the way, they encounter two mysterious and powerful newcomers, Pietro and Wanda Maximoff.
(via Film Sketchr)