Cheyney Spit is located in the Thames Estuary, just off the coast of the Isle of Sheppey, Kent. It can be seen on this chart.
The overlays that highlight 17th century London features are approximate and derived from Wenceslaus Hollar’s maps:
Open location in Google Maps: 51.447588, 0.794448
Chart showing the number of references in each month of the diary’s entries.