Okay, so working on this challenge.
The image is a track and field track, not a football stadium (so, I don't really know how we got off on that tangent).
Anyways, the clue...(I like this clue much better than the other one, "river where 2 countries meet in a line" gave me nothing to work with)
Use the old ways to add 5.5 yards to the back of AU
And find the new land where it grows
5.5 yards = 1 pole (or rod or perch)
So, old ways might have to do with that (i.e. those units of measure are "old"), or it could mean something else.
AU=? Could just be the letters AU, Astronomical Unit, Gold,...not sure of anything else.
So, if we add pole, etc to the "back" of those we could get
Aupole, Aurod, Auperch
Goldpole, Goldrod, Goldperch
(obviously astronomical unit doesn't fit there)
So, of those the most obvious choice for "growing" would be the plant goldenrod. Less obvious would be aupole-sounds kind of like apple?
Let's go with goldenrod...
According to wikipedia:
It is most common in North America, but has been introduced to Europe.
Well, depending on how "new land where it grows" is being used here that could be North America (as a new land relative europe) or Europe (being where goldenrod newly grows). Moving from there might need more particulars about goldenrod (assuming goldenrod is in fact correct).
When there, find the site of an old world battle
Is the next step. So, what is the potential site of an old world battle that can be tied into this?