To ask what these are?

[dee103]

i.redd.it/as299nbavc731.jpg

Reddit link is because I tried to ask on there but my post got deleted for some reason. Recently moved into a new house and was walking around the new area and came across this field. It has a little park and a football pitch. These things are surrounding the perimiter of the field. I thought they were seats at first and thought about what a stupid design they were but thinking about it I'm not sure they are seats. There are loads of them, more than I can count.

I know it's silly but these are really annoying me and I need to find out

Are they for slotting in the poles to make temporary goals for the football pitches?

Could they be for mounting floodlights or something in?

(I'm really just marking place because I want to know now!)

Did they once contain metal fencing posts and the rest of the fence has been dismantled?

I think they are for putting lights in when playing at night

A fixture base for a big marquee maybe?

@ItsAllGoingToBeFine Since you wanted to know (glad I'm not the only one )my neighbour has just told me the field is on top of an old rubbish tip and they go right under the ground to release the gasses from the rubbish.

I'm glad the mystery is solved...

You should try dropping a match down one