This is the Reichserntedankfest of 1934 in Buckeberg. That year, 700,000 people participated. Even those who did not support Nazis were totally blown away and emotionally shaken. They had never experienced anything even remotely like this, there was no rock concerts back then. It created spiritual feeling of sublime and unity among people who were participating. When they were marching back to their tents in the night, they could still see the huge spotlights piercing the sky in the Buckeberg. They were totally pumped up and fell that things are really going to change better.
Photos of these rallies are often mistaken for Nurnberg. That was the “Reichsthingplatz” at the Bückeberg hill in northern Germany, near Hameln, used for harvest celebrations (“Reichserntedankfest”), 1933-37.