For a city, that’s one long path through a large dense forest. Or is that like a highway approaching the city? Do people camp there, or party there?
That's Tiergarten, a large park in the middle of Berlin - it's so central that at one end is the Brandenburg gate (you can see at the end of the road in the picture) and on its side it borders the residence of the President (this one is actually a bit inside the park), the one of the Prime Minister (Kansellerie) and the German Parliament (Bundestag).
Also the well known Berlin Angel is in a rotunda about 1/4 of the way along that avenue just behind where this picture was taken (the picture is facing the longer stretch of that avenue).
It's a lot longer than it's wider and the picture was taken along it's longer axis plus the lens choice and angle makes it seem even longer, plus it's in Portrait rather than Landscape - the same picture in Landscape orientation would show stuff outside the park.
I lived a couple of months in Berlin and would go for a run around the park maybe twice a week and doing a loop of the whole thing near the outer boundary is around 10km.
Link to article?