Outdoor facility - Neighbor has already built a wall

The wall is perfect for drilling into it. Looks like exposed aggregate blocks.

But it belongs to the neighbor.

straighten it normally?

Straighten? What would that mean?

I would - if it were on my property - ask if the wall can/may be plastered.

That would be - as far as can be seen in the picture - the visually and technically "correct" solution.

So that we also have a ground-level lawn area

talk to the neighbor maybe he wants it too and you share the costs.

Oh, bushes are going there as a privacy screen anyway, so no plastering.

talk to the neighbor maybe he wants it too and you can share the costs.

We have to look anyway, they want to build a carport which we have to approve because it is too high. But we will not approve it because the rooms on that side will no longer get any light.