An aftercastle (or sometimes aftcastle) is the stern structure behind the

mizzenmast The mast of a sailing vessel is a tall spar, or arrangement of spars, erected more or less vertically on the centre-line of a ship or boat. Its purposes include carrying sails, spars, and derricks, and giving necessary height to a navigation lig ...

and above the transom on large sailing ships, such as carracks,

caravel The caravel (Portuguese: , ) is a small maneuverable sailing ship used in the 15th century by the Portuguese to explore along the West African coast and into the Atlantic Ocean. The lateen sails gave it speed and the capacity for sailing win ...

galleon Galleons were large, multi-decked sailing ships first used as armed cargo carriers by European states from the 16th to 18th centuries during the age of sail and were the principal vessels drafted for use as warships until the Anglo-Dutch W ...

s and galleasses. It usually houses the captain's cabin and perhaps additional cabins and is crowned by the poop deck, which on men-of-war provided a heightened platform from which to fire upon other ships; it was also a place of defence in the event of boarding. More common, but much smaller, is the forecastle. As sailing ships evolved, the aftercastle gave way to the quarterdeck, whose span ran all the way to the main mast.

References

Sailing ship components {{Water-transport-stub fr:Dunette