| Answer | Crossword Clue |
|---|---|
| SCHIST | Rock used in walls |
| BREASTWORKS | Low walls used as a defense in battle |
| RIPRAP | Broken rock used in foundations |
| RIPRAP | Crushed rock used in foundations |
| LICHEN | Growth on rock walls |
| SCALED | Like fish and rock walls |
| SCALED | Like maps, iguanas and rock walls |
