Related Clues:
- Equine mothers
- Water-filled ditches as fortifications
- Creators of reservoirs
- Beaver creations
- Defensive water-filled ditches
- Medieval barriers
- Rings of water around castles
- Surrounding ditches
- What beavers build
- Barriers at animal parks
- Deep defenses
- Some farm mothers
- Defensive trenches
- Sites for fish ladders
- Fish ladder settings