uncovering something odd beneath the paving....

Hi all - bit of an odd one this... as my signature might suggest, this year i have undertaken the task of trying to get my sisters garden into shape, largely in vain hope of making it a safe place to play for my nephew. After 4 weekends of digging, removing stones, concrete and glass from all corners of what isnt exactly the biggest garden, i have stumbled upon some metal blocks that i really havent a clue what they are!
If anyone could shed some light on this it would be really appreciated as they are very heavy (metal) and look totally out of place considering where i found them (ie, under paving slabs at the end oof the garden!)

 

sorry jos brother cant help even asked the hub (builder)he hasnt a clue, do you live beside railway lines ? just a wild guess

 

Just guessing, but they look like something to do with drainage, maybe.
I assume they are made of cast iron.

 

They could be out of a coal fireplace perhaps.

 

Didn't they used to call that 'pig iron'? I seem to recall learning about it all those years ago at school........ it's to do with the shape apparently

 

Part of an old fire range/oven?

 

I think Palustris is right, the grove bits are where the shelves used to sit.(sides)

 

Tel the coppers it's an old cage that might have held a body. They'll dig your patio area for you :D

 

Oh I like it....What knowledge....Re Coppers!