The bulk of the book consists of maps, images, and floorplans of medieval European castles from .
It also includes:
- A quite comprehensive glossary of terms related to castles and other fortifications
- A short bibliography for further reading on the topic
- A wall rating system for comparison, based on number of hits by various sizes of stones launched by siege engines
If you have an interest in applying real-world castles to your gaming, this is well worth a look.