Cherbourg Harbour Project
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The Cherbourg Harbour project was a project to fortify one of France's northwest harbours in the late 18th century. Cones were submerged in the waters around Cherbourg initially, and then replaced with a masonried rubble structure once this was deemed unfeasible.
Construction took nearly a century, from 1784 to 1850. It was designed to provide a safe habour for the French Navy to defend against the English navy.