After heavy rain and flooding caused by Storm Henk, the clear outline of a 400-year-old English Civil War fort, The Earith Bulwark, has been revealed in the Cambridgeshire Fens. Built around 1643 by Oliver Cromwell’s forces, the fort covers approximately 60 square meters with bastions at each corner. Historic England considers it one of the most elaborate fortifications from the Civil War.

The bulwark, strategically located on the Hundred Foot Washes, protected a vital river crossing at the western end of the fen causeway linking Huntingdon to the Isle of Ely. Designed by English engineers Richard Clamp and Captain John Hopes, it reflects Dutch military fortification principles. The central enclosure, raised 0.7 meters above ground level, is surrounded by an earthen rampart and parapet, with bastions forming diagonal projections at each corner. The bastions served as artillery platforms for wide-ranging fire and close-quarter defence. The fort’s appearance is rare and occurs primarily after extreme flooding.