What is this little fenced off area in Rustboro City for in ORAS?

Every time I go into route 115 from Rustboro City, there is a small opening in the fences that leads to a grass area that is 3x3.

What is it for?

Solution 1:

I assume you're talking about this area, off to the side of Rustboro City:

Which in context is here: _Bulbapedia

There seems to be nothing special about the area.

• There are no hidden/visible items there
• It isn't part of the main story, nor the 'Delta Episode'
• There are no events/side quests that use the location
• It is not a secret base

It is either an oversight by the developers or simply a small design choice of the area.*

_{*Judging from the relatively small size, perhaps they couldn't fit another Tree sprite (like the ones surrounding it) in the spot.}

Solution 2:

As far as I am aware, there is no real reason for this, just part of the map.