How many castles are there in the world?

There is no known number of castles that are available in the world because there are just so many that can be found. For example, there are thousands that can be found in Europe alone, and there are also quite a few that can be found in the United States.

There are some places in the world wherein castles have not been built, but this does not change the fact that there are so many castles located in various parts of the world. Some castles are still lived in by people, although they may not be from the royal family anymore. Some may be able to live in castles temporarily through renting out some rooms in the castle.