Castles are fortified residences built during the Middle Ages by nobility. These giant structures served as symbols of power, as well as serving offensive and defensive functions. A castle was not only a means of protecting the land of a wealthy Lord, it also served as a location to house armies and stage invasions and raids on neighbors. Castles were first built in the 9th and 10th century, and continued until the 16th. Almost all castles are located in Europe, Russia, and the Middle East, with a few more modern exceptions.
Early castles were not made of stone, but were rather built from earth and lumber. These castles were later upgraded in many parts of the world into the stone castles we see today. As military technology progressed and gunpowder artillery became common, castles lost their military significance and became mainly status symbols.
The Motte and Bailey style of castle is one of the most well known, with a central keep built on a hill surrounded by high walls and fortifications, and a protective ditch around the outside. This ditch, often flooded for extra defense, was dug first and the removed earth was used to create the hill which the keep would sit on top of. This type of castle can be found most commonly across the United Kingdom, the Netherlands, France, and Ireland.
Spur castles are another important castle type, which uses its location as a key to its defense. The ideal spur castle is built into steep hills or cliffs, so that the majority of fortifications only have to defend from one side. These castles can provide key strategic importance when built in locations where a potential enemy is forced to approach through one heavily fortified route.
Many castles were also created during the Crusades, which generally ranged between the years 1095 and 1456. These invasions and conflicts between European empires and Muslim empires stretched across huge areas of land, and the resulting conquests of land required castles for defense and offense. Cyprus, Israel, Jordan, Lebanon, Syria, and Turkey all had castles built or rebuilt on their land as a result of the crusades, and many of them still exist today.
There are many other parts of the world where "castles" have been built, but these structures are almost never true castles. Homes and forts built to resemble castles have been constructed widely in China, the United States, Canada, Mexico, and throughout Africa. Be careful when planning tourist trips to locations where castles are not known to be common. Many locations claim castles, and they may include impressive stone buildings, but very few are authentic stone castles.