Take a tour of a medieval castle. Every part of the castle has a function. Walls keep the enemy out. Towers protect the lord and the soldiers. From the moat and portcullis to the great hall and dungeon, see how a castle works as an enemy army tries to storm the walls. Castle: How It Works is a Kirkus Reviews Best Children's Book of 2012 | Castle: How It Works by David Macaulay, Paperback | Indigo Chapters