The Chess pieces at either side of the board get their English name from the Persian word for "chariot" (rokh), originally a Sanskrit term (rath). The explanation is that some chariots were once designed to look like mobile fortifications, or they may represent siege towers. Certainly you would not be transporting a stone castle from place to place.
The piece that looks like a "castle" is called a "rook".
A Rook is sometimes called a tower or castle by amateurs of the game.
It's called a castle. hope this helps!
Historically , the rook symbolized a chariot and the Persian word "Rukh" meant chariot .
Another name for a rook is a castle.
A castle, tower, marquess, rector, or come. However, it is almost always called the rook.