Tilbury Fort, London, England. Work on the current fort was begun in 1670. The original blockhouse was retained, and work, often accomplished by pressing labor from nearby towns, continued into the 1680's. Scottish prisoners taken at the Battle of Culloden in 1746 were held at Tilbury Fort. Ten armed hulks were arrayed across the Thames in 1803 in an effort to block a French invasion... antiaircraft guns on the fort's parade ground shot down a Zeppelin airship in WWI.