A.T.T Landscaping

[A.T.T.]

I'd love some suggestions and opinions on what to do with this. This is my house, a couple months ago I ripped out the above ground pool that was there for 18 years and scrapped it. I'd like to replace it with some form of landscape, I'm thinking a water feature of some sort. You can see the edge of the garden where it drops off, that will be held back with a retaining wall of some kind, maybe armor stone, maybe some kinda of versalok type brick. The base of the pool is all sand though, and water does seem to collect there as you can see. What would you do? The cost is relevant, labor is free. And I think I might be able to dig up some nice sized rocks myself around our property.