Give that man a hand!
During the fight with Iron Man in Washington Square Park, Cull Obsidian is transported onto a frozen wasteland by Wong. When he tries to escape, Wong closes the portal, cutting off the alien’s hand.
According to the credits of the film, plate photography was conducted in numerous locations including Alaska and Norway. The terrain here does not look like Alaska, but Cinefex #159 mentions plates being filmed in Svalbard, Norway (a Norwegian archipelago). Looking at photos from that area, such as ones from Edge Island or the Nordvest-Spitsbergen National Park, this seems like a much more likely prospect.
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(Avengers: Infinity War, 2018)
MCU: Location Scout 