Castle

A Castle is a fortification built to control territory and may be the home of nobility who own the territory. They come in many forms and exist in many parts of the world.

Description
Typically, a castle will have walls, various buildings, a water source, and hold a strategic position, but some castles don't have one or two of these. For example, many European island castles don't have walls, while small castles like Mie Castle don't have buildings or a water source.

Castle walls can be made of earth, wood, stone, brick, or concrete. They can be high and thick or low and angled. They can be flat or have parapets atop them to protect defenders. They can have a single wall surrounding the entire castle, multiple rings of walls, or mazes to confuse enemies. They can also be shaped to provide better defense, such as a triangle or star instead of the classic square or circle.

Inside the castle walls, the castle can be a complex of buildings or one large building. The largest building is usually the home of the castle's owner. Buildings can be made from various materials like the castle walls. For example, many Japanese castle buildings are made of wood and covered in fireproof plaster.

As for a water source, many castles are built on or near a source of fresh water, such as a river or a spring. A well or cistern is often built within a castle.

Because the main purpose of castles is to control territory, most castles are built on or near strategically significant locations, such as a hilltop or along a river.

Castles, Shiro, and Gusuku
While castles come in different forms, they are markedly different between cultures, and yet share some characteristics. For example, most buildings within East Asian castles are made of wood, while buildings within European castles are made of stone. Architecturally, the buildings inside Ryūkyūan castles are very similar to Chinese castles.

Ryūkyūan castles, called gusuku, utilize stone blocks fitted together and are known for their long, snaky walls. Japanese castles originally had earthen and/or wooden walls, but after the introduction of gunpowder weapons, they adopted stone block walls.

Most Ryūkyūan castles were built during the Gusuku Period (1187–1429), and they were usually superior to their Japanese contemporaries.