North of Eynsham (which is west of Oxford) the nearest main road is the A40 and it looks to be agricultural land.
If you look straight up from Eynsham, there's a road called Lower rd and to the left there's a road called Cuckoo Lane , the crossed hammers section is between these 2 roads.
Sorry , I've just read the replies , apparently they're open mine works (i suspect, given the local geography, these are gravel woks.
Thanks anyway
Ed
https://wiki.openstreetmap.org/wiki/File:Mine1.svg
Open Mine works
Where do you see them?
Does anyone know what these symbols are