I have eyes on Loki. 14th Floor.
Steve tries to escape Stark Tower with Loki’s scepter, but is intercepted by his 2012 counterpart and ends up having to fight him.
While this looks like a real location, it is an entirely CGI built set. According to Cinefex #165 p76, it was modeled after DNEG (effects company) facility. An in-depth explanation of this effect can be seen in the following YouTube video How Avengers: Endgame’s Visual Effects Were Made | WIRED.
(Avengers: Endgame, 2019)