A milecastle was a small rectangular fort built during the period of the Roman Empire. They were placed at intervals of approximately one Roman mile along several major frontiers, for example, Hadrian's Wall in Great Britain.
Along Hadrian's Wall, milecastles were initially constructed of stone in the eastern two-thirds and stacked turf with a wooden palisade in the western third, though the turf milecastles were later rebuilt in stone.
Size varied, but in general, they were about 15m by 18m internally, with stone walls as much as 3m thick and probably 5m to 6m high.
On Hadrian's Wall, a milecastle usually guarded a gateway through the Wall.
The SS America, a remarkable ocean liner and cruise ship designed by the renowned naval architect William Francis Gibbs, had a rich history spanning 54 years from its construction in 1940 until its tragic shipwreck in 1994.
In October 1992, the ship was sold with ambitious plans of transforming it into a luxurious five-star hotel ship off the coast of Phuket, Thailand. The grand vessel was renamed American Star and underwent significant modifications: its propellers were removed and placed on the deck at the bow, the funnel was painted red, and ladders were welded to starboard, all in preparation for the tow.
In December 1993, American Star embarked on its final journey, leaving Greece under tow by the Ukrainian tugboat Neftegaz-67. However, fate had other plans for the majestic ship. While sailing in the Atlantic, the vessel encountered a fierce thunderstorm, causing the tow-lines to snap. Desperate efforts to reattach emergency tow-lines proved unsuccessful, leaving the ship adrift.
In a daring rescue operation, the crew aboard American Star was evacuated by helicopter on 17 January 1994, just before the ship went aground in the Canary Islands at 6:15 am on 18 January. Amid ongoing discussions among the ship's owners, the towing firm, and the insurance companies, the once-grand vessel was left to the mercy of nature.
Within the first 48 hours of grounding, the relentless pounding surf of the Atlantic mercilessly broke the ship in two, just past the second funnel. The ship's tragic fate was sealed, and it was officially declared a total loss on 6 July 1994.