Grotte di Frasassi, Genga

The Grotte di Frasassi, in the gorge of the river Sentino near Genga in the province of Ancona, are among the most spectacular show caves in Europe and a highlight of inland Marche. Discovered in 1971, the cave system extends for kilometres beneath the limestone hills and opens with the Abisso Ancona, a single underground chamber so enormous that, as guides like to point out, Milan Cathedral could stand inside it. Within, the caves are filled with an extraordinary array of karst formations: towering stalagmites, hanging stalactites, delicate draperies and flowstone, slender soda-straw tubes and still underground lakes that mirror the rock above, all dramatically illuminated for the guided visitor route. Because the caves are lit artificially and visited on timed tours, the time of day is irrelevant to the interior photography, and the practical challenge is the low, contrasty light: a fast lens with a steadied raised ISO is essential, since tripods are generally not allowed on the moving tour and flash is discouraged. The vast scale rewards a wide-angle to convey the size of the chambers, while care with the strong spotlights helps control highlights on the wet formations. Outside, the approach through the dramatic Gola di Frasassi gorge, with the Romanesque abbey of San Vittore alle Chiuse at its mouth and the Tempio del Valadier carved into the cliff above, offers its own subjects, best photographed in morning light when the valley is illuminated. Tickets are timed and should be booked, and the cave interior is cool year-round, so a layer is advisable. Combining the underground spectacle with the gorge and its monuments makes Frasassi one of the most photogenic excursions in the region.