Boundaries, these days we are all subjected to them: Tier 1, Tier 2 and Tier 3, it just depends on what side of a border that you reside.

So how about Kent being on the north side of the Thames? North Woolwich, which of course, lies on the opposite bank, was for more than 800 years, technically a part of Kent. The Woolwich Free Ferry and the Woolwich Foot Tunnel did their best at connecting both halves. It started, as often the way, with William The Conquer, who gave Hamon de Crevecoeur in 1086 both banks, and in all likelihood rights of charging river traffic.

It wasn’t until 1965 that North Woolwich was transferred to the Borough of Newham, but we still have two places called Woolwich.

Or being a London borough but outside the M25. North Ockendon is inside London, but outside the M25, while South Ockendon, a short walk away, is in Essex and outside the M25.

So just how many live inside the M25 but outside of Greater London? According to estimates, about one million, living in 21 districts which straddle the M25. When describing infection rates it might be a psychological buffer zone but not according to cartographers.

Image creative commons, but including Ordnance Survey data © Crown copyright

Postcode should be pretty localized, we have after all ‘postcode lotteries’. When they were first introduced on New Year’s Day 1858 London was divided quite logically into 10 segments: EC, N, NE, E, SE, S, SW, W and NW. Less than a decade later there was talk of changing this logical sequence, NE London found its way to Newcastle-upon-Tyne and S London migrated northwards to Sheffield, where they remain to this day.

Just as oddly, Havering, Hillingdon, Barking, Dagenham and Sutton are not London postal districts even though they fall mostly within the M25, but Sewardstone in Epping does, despite being nearly 12 miles from Charing Cross, outside the M25, surrounded by a forest and having been given the postcode E4.