EC4N: 1.0 m clear of the highest tide in the London Bridge ledgers

The lowest postcode in EC4N, EC4N 8AR, stands 1.0 m above the highest tide in the London Bridge ledgers (5.41 m, 1 February 1953). The highest, EC4N 6EH, stands 12 m above it.
- Ground at eight in ten of its postcodes: between 11 m and 16 m, measured from Ordnance Datum; the middle one stands at 14 m.
- None lies in the Environment Agency's Flood Zone 3 from the sea.
- Mostly in City of London; partly in Islington.