If you look at the shape of the field, it’s pretty clearly an American football field (not to be confused with soccer, which non-Americans call football). A soccer field, for instance, isn’t as long and narrow as this.

From there, it’s pretty easy to guess that it’s in the US, and the everything-everywhere map doesn’t list too many US locations. So start with a map of the professional teams, and hope it doesn’t turn out to be a college team (of which there are more).