One or two of the plotted Roman road routes may have slight alignment issues as places and names have changed over the last
60 years since the books by Ivan Margary were published, making it very difficult to match locations exactly.
The high tide changes in the coastline shown in pale blue, and the 5 metre high tide mark on the rivers shown in dark blue.
The coastline of Essex is very different from today, with the area around the Thames, Canvey, Mersea and Brightlingsea areas
being salt marsh with small islands.
For the rivers, the 5 metre mark is shown however the tidal reach could be further inland due to the back
pressure from the rivers upstream.
The purple line and shaded area shows the present county boundary.