Patio stone leveling dilemma

[jstonemo]

I am going to spend the extra money this time and install a stack stone retaining wall. The previous pool completely rusted through at the bottom. I didn't find much left of the bottom plates and wall track either. This was after 7 seasons.

The stones ended up being 1-1/4" off level across the width of the pool. Spent the day resetting the stones. I was surprised it had settled that much after only 7 years.