The south-eastern edge of London has two places called Green Street Green.
One is near Dartford https://www.google.co.uk/maps/place/Green+Street+Green+Rd,+Dartford,+Kent+DA2/@51.424725,0.2393939,13z/data=!4m2!3m1!1s0x47d8b3e62bfbb5c9:0x4bf29b48af7caf3e
and the other is near Orpington...