CLUES
- Ibadi Muslims established a community in this region in the 10th century.
- Five fortified villages, or ksour, constitute walled citadels that contain a mosque surrounded by houses built in concentric circles.
- Mosques here were conceived as fortresses. They served as watchtowers and included arsenals and grain storage.
- The settlements have influenced Arab architecture and planning for nearly 1,000 years.
ANSWER M’Zab Valley, Algeria