Hi guys.
I'll preface this by saying I'm not great with DIY, but I'm willing to make an effort.
Pretty much, the back garden of the house has been neglected for years. It's been, essentially, a 'city dump' of sorts. It was disgusting.
Anyway, after a good effort today, the vast majority of the garden has been cleaned up, and looks a lot better. We hired a skip, and three of us got stuck in for the day.
I want to improve the garden in general. But I'm trying to tackle it 'one thing at a time'.
Here's a photo of a section of the garden, after our clean up today.

Effectively, the muck there has been there years. It's been there since the shed to the right was built. It was supposed to be carted off in a skip about 5 years ago, but laziness meant it never was.
Although it's cleaner, its still dire. I want to do something with it, but not sure what. The options as I see them are to...
1) Get another skip, a shovel, and throw all the cement blocks into the skip, and shovel away at the muck until it's all 'ground level'. Effectively, bin the whole lot of it.
2) Get a skip, get rid of the concrete blocks, and try to spread the muck out and level it off so it takes up the whole area. Keep the muck, but replace the bricks with something more presentable (coloured bricks, wood, fence/railing etc). Plant a few flowers or something.
3) Get a skip and get rid of the concrete blocks, try to put down some kinda garden tile or something on the mucky area that kinda 'ramps' down on the right, and make the 'rampy' section into a 'floor', and then make a square flower bed of the rest of it.
Either way, the horrendous looking concrete block divide thingy has to go into the bin. That's not staying. But I just dont know what to do with the muck itself. Bin it or keep it. My fear is that if flowers or such are planted, although theyll look nice, they wont be maintained and in a months time it'll be back to a mucky sludgy mess.
Has anyone got any ideas that can possibly be employed here to clean this area up a bit?
Here's a slightly wider shot of the garden:

There's obviously a lot more to do, but this small section of muck is my priority (cos it's annoying me) then I'll attack the shoddy doors on the sheds, etc. as I go along.
Cheers to anyone able to offer any insight or ideas here