EC4A: 0.8 m clear of the highest tide in the London Bridge ledgers

The lowest postcode in EC4A, EC4A 4BL, stands 0.8 m above the highest tide in the London Bridge ledgers (5.41 m, 1 February 1953). The highest, EC4A 1JS, stands 14 m above it.
- Ground at eight in ten of its postcodes: between 8.2 m and 18 m, measured from Ordnance Datum; the middle one stands at 15 m.
- None lies in the Environment Agency's Flood Zone 3 from the sea.
- Mostly in City of London; partly in Islington.