In reply to Rog Wilko:
> How about lowering the manhole covers? This is not an attempt at humour, but a serious suggestion.
It might well be easier than levelling the entire garden. Depends on the manhole construction, if it has regulating brickwork it's fairly easy. However mypxrex isn't a young bloke, and breaking out the concrete and removing the cover and frame intact (he says iron covers) will be hard work.
Mypyrex, as has been said, a 800l dumpy bag of topsoil won't break the bank, but it will compress down. You could get a couple of bags for £100 or so, it always comes in handy for topping up the beds.
Edit: Paving it is a lot of preparation to do a half decent job, and it'll be harder work and cost more than either of the above options.
Post edited at 09:44