Broken Glass

Why is there so much broken glass in my garden?  Am I developing the first glass garden? Some of it is bottle glass, I even found one whole small bottle.  Most of it though is clear glass, thinish, plate.  I think it is probably from a long-gone greenhouse.

When I bought the garden (I bought the garden, the house just happened to come with it), the garden was largely a big lawn with a couple of trees.  No sign of a greenhouse that might have been there.  When digging the pond the glass started to emerge and suddenly I realised that there was quite a lot of it.  Plus a fair amount of old bolts and bits of wire. 

So should I call in Time Team?  Get Tony Robinson to find the source of the glass and amaze my neighbours with the glass-age village that used to be present on my back lawn?

Maybe not - I shall just continue picking it up and humming Nick Lowe songs whilst I do so.