31st January 2024. Dawn in Gravesend, followed by a trek around the North Kent marshes: Higham, Cliffe and Cooling. The skyline dominated by the cranes of the Essex ports, across the water of the Thames Estuary: Tilbury and London Gateway. But on this side, the abandoned forts of Shornemead and Cliffe, ponies grazing between the shore and the bog, and a sliver of a path tracking around the wetlands, where the remains of a long-forgotten army base marks its traces. 15 miles.