[granjan]

Perhaps we could do with Time Team to give us some of the history.  I've found big hand made nails as well 

[stentman]

Baldrick and his pals may well fill in the history for you but what about all the digging? Any chance you could use them for bean trenches

[mumofstig]

now that's a good idea.....but knowing them someone else's plot would have better geophys 

[andy135]

You're all better off than me. I've got a rusty nail mine and they are still coming out four years on.

There are supposed to have been some good gardeners on the allotment before me. Perhaps they grew nails. 

Maybe people have burnt old timber on the plot in the past to provide ash. and that is where the nails are coming from?

[HilaryG]

I looked at our plots on google earth today (was getting withdrawal symptoms). They would make a great picture for the wall at home! 

[sunshineband]

Can you see the stones if you zoom in?