I had an old pond I've now drained, right in the corner of my garden. I now want to put a shed in the same spot but the land isn't level. The soil level all around that corner is about 18" higher than the lawn. I'm happy for some kind of block-work/brick base to be built & the shed go on top of that with steps up, or any other ideas you might have? I can't excavate the area as I'd destabilise both of next doors fences. There's also a large mature tree just to the right of the picture & it's roots probably go through the corner too. Obvs all the greenery will be cut back.