The last time I was in Germany and saw a man standing above everybody else, we ended up disagreeing.
In order to steal a rare element to power his portal machine, Loki stages a distraction (and grabs some intel) at a museum party in Stuttgart, Germany.
According to the SHIELD intel, the location where Loki was discovered was Stuttgart, Germany, 28 Königstrasse.
All of the exterior scenes in Germany, including the fight between Loki, Iron Man, and Captain America, were filmed in Public Square, Cleveland, OH.
MAP
(The Avengers, 2012)
MCU: Location Scout 