The 11 km of the SP. 142 road (ex SS. 71) that lead from Bagno di Romagna to the Mandrioli Pass (1178 m asl) are a spectacular journey through geology and nature. This road was built between 1870 and 1882 according to a project by the engineer Alcide Boschi (1839-1892) and offers different scenarios depending on which side you are driving along. Along the Romagna side you climb for a spectacularly striking 11 km along a road carved into steep rocky slopes, which unfolds smoothly over 27 hairpin bends and short straight sections.

The route is set in a terrible, yet fascinating, landscape of rocky outcrops and deep ravines with bare walls layered with sandstone and marl that form horizontal "steps" as in the "Scalacce" (the Rough Steps) or the vertical slabs of the "Tavole di Mosè" (Tables of Moses). The landscape erupts with greenery against a grey background and clearly shows the turbulent geological history of this area. The view offers an example of the marl and sandstone formations of Romagna with layers of sandstone (yellowish and resistant to erosion) alternating with marl (grey and flaky) to create an enormous prehistoric sandwich where slices of marl and sandstone sedimented on an ancient seabed that formed the Apennines as it emerged.

With the opening of the E45 road, the Mandrioli Road - once called the "Tosco Romagnola" Road - has lost its importance in connecting Romagna and Tuscany and has been downgraded to a "Provincial Road" , but this makes it more enjoyable for those who want to unhurriedly admire the landscape and panoramas that have enchanted travellers and artists through time.