Gola del Bottaccione

Bottaccione Gorge lies between Gubbio and Monte Foce, where steep limestone layers reveal the region's geological history. The gorge is also crossed by a medieval aqueduct that still carries water toward the city.

Why it matters

The Scaglia Rossa limestone preserves the Cretaceous–Paleogene boundary, where an iridium anomaly helped Luis and Walter Alvarez develop the meteorite-impact explanation for the extinction of the dinosaurs. In 2022, the international geological commission ratified a section of the gorge as the Global Boundary Stratotype Section and Point for the base of the Campanian Stage.

What to notice

The gorge's exposed rock layers record sediments deposited on the sea floor between about 140 and 30 million years ago. Along the slope runs the medieval aqueduct, an approximately 1.6-kilometre channel that drops about 25 metres toward Gubbio. Its remains link the geological landscape to the city's historic water supply.

Context and history

The aqueduct was extended in 1327 to capture a spring on the Monte Foce side and roofed in 1377. Repairs are documented in 1435 and 1492; Pope Clement XII contributed to further restoration in 1733. The gorge's unusual geology later became central to research on the Cretaceous–Paleogene extinction event and the definition of geological time.