Grotta del Buco dell'Orso

High on the mountain of Torriggia, some 600 metres above Lake Como, opens the Buco dell'Orso — the Bear's Hollow. The karst cave takes its name from fossil bones of the extinct cave bear discovered here from 1849 onward.

Why it matters

For a small lakeside comune, Laglio holds an unusual scientific story. In the summer of 1849, Vincenzo Barelli discovered a bone fragment inside the cavity. Subsequent excavations yielded fossils that the palaeontologist Emilio Cornalia studied and documented; many specimens were donated to collections. The discovery was reported well beyond Lombardy, and professors and scientists travelled to Torriggia to see the cave for themselves. Secondary local sources record that many of the bones belonged to the cave bear, Ursus spelaeus, an extinct species of the Pleistocene, with skeletons later distributed between the natural history museum in Milan and the local town hall.

The cave is a karst cavity with stalactites, stalagmites, an underground stream and a pond. Its spring feeds the local aqueduct, which is why the cave is protected.

What to notice

• The palaeontological deposits: the cave floor and its side passages yielded layered fossils, many now held in museum and municipal collections.
• The underground stream and spring, part of the hydrology that sculpted the cavity and supplies nearby villages with drinking water.
• The successive limestone strata, which reveal a cross-section of the mountain's geology.
• The setting on the slopes above Torriggia, overlooking the lake near its narrowest point and the village of Careno.

Context and history

The cave's fame is a 19th-century story. When Barelli's fragment came to light in 1849, bone-hunting in Lombard caves was becoming a science, and Torriggia's finds arrived at the right moment: Cornalia's memoir placed the site in the scientific literature, and the "bear hole" name fixed the association with Ursus spelaeus in local memory. The specimens left the mountain for the Natural History Museum in Milan and the municipio of Laglio, while the cavity itself kept its stalactites, its pond and its unexplored continuations — secondary sources describe the cave system as never entirely explored.

The cave's modern history is shaped by protection of its drinking-water source. Its spring continues to supply the local aqueduct, preserving an important connection between the karst landscape and the surrounding communities.