| SARDINIA | Mediterranean island south of Corsica with some 7,000 stone structures known as nuraghi dating from the Bronze Age (8) |
| SAR | Island south of Corsica: abbr. |
| HAMMERHEAD | Shark with eyes positioned at either end of a structure known as a cephalofoil |
| WALPOLE | Author of The Castle of Otranto and some 7,000 letters who was the youngest son of Britain's de facto first prime minister and created Strawberry Hill House (7) |
| DOLMENS | The same liberal convenience in stone structures (7) |
| PILLARS | These 56 stone structures represent the states and territories extant when 19-Across ended |
| GRANITE | These 56 stone structures represent the states and territories extant when 19-Across ended |
| MALTA | Mediterranean island south of Italy |
| CYPRUS | Mediterranean island south of Turkey |
| LEAF | A folio of a book; a botanical structure known in its embryonic form as a cotyledon; or, gold in the form of foil, used in gilding (4) |
| WALL | A vertical brick/stone structure an athlete metaphorically hits during the state of fatigue known as the bonk (4) |
| AJACCIO | City on the west coast of Corsica best known as the birthplace of the Emperor Napoleon |
| LIGURIANSEA | Arm of the northern Mediterranean lying between NW Italy and the island of Corsica (8,3) |
| ROOT | A structure known in its edible form as a carrot, parsnip, radish, swede or turnip, for example (4) |
| TYRRHENIANSEA | Arm of the Mediterranean between Italy and the islands of Corsica, Sardinia and Sicily (10,3) |
| BASTIA | Capital of the French department of HauteCorse, on the NE coast of Corsica (6) |
| AVOIRDUPOIS | Imperial system of weights based on a pound of 16 ounces or 7,000 grains; from French, 'goods of weight' (11) |
| TOWER | Bell -; structure known in Italian as a campanile (5) |
| CROSS | Symbol marked in dough on the top of a fruited spiced bun that is traditionally eaten on Good Friday; or, a stone structure used to indicate the site of a town's market square (5) |
| CATERPILLAR | A wormlike lava may provide what is required of an upright stone structure |
