Location: Bossea Localita, Commune Frabosa Soprana, Piedmont Map
Tel. 0174 34 92 40
Open: Mon- Sat 10am- 4:30am
Sun public
holidays 10am- 5:30pm
Closed: Dec 25, 1 Jan
Prices: Adults 10 Euro
Children (under 10 yo) 7 Euro
Tourists /w disabilites Free
The
Grotta di Bossea (Bossea Cave), located in the Val Corsaglia within the
municipality of Frabosa Soprana in the province of Cuneo, Piedmont
region of northern Italy, is a renowned show cave celebrated for its
majestic karst formations, underground rivers, and scientific
significance. Situated at an elevation of 836 meters above sea level in
the Ligurian Alps (part of the Maritime Alps subgroup), the cave extends
over approximately 3 kilometers in length (with about 2 kilometers
accessible to visitors) and reaches a depth of around 780 meters,
featuring a total elevation gain of 116 meters during tours. It forms
the terminal section of a vast karst aquifer system in the
Maudagna-Corsaglia watershed, between the Prato Nevoso basin and the
Corsaglia River, and is characterized by immense chambers, towering
concretions, underground lakes, and a perennial torrent that traverses
its lower zones. As one of Italy's most important and beautiful tourist
caves, it attracts around 30,000 visitors annually and has been a site
of continuous scientific research since the 19th century, making it a
unique blend of natural wonder, paleontological treasure, and
environmental laboratory. The cave maintains a constant internal
temperature of 9°C and 100% humidity year-round, creating a damp, stable
microclimate that supports diverse subterranean life and requires
visitors to dress appropriately.
The history of Bossea Cave dates back to its initial exploration in 1850 by a group of local valley dwellers led by Domenico Mora, who ventured into its depths and documented its features. This marked the beginning of systematic interest in the site, with further excavations starting in June 1865 that uncovered significant paleontological material, including bones of the prehistoric cave bear (Ursus spelaeus). On August 2, 1874, it became the first cave in Italy opened to the public, thanks to the efforts of Senator Giovanni Garelli from Mondovì, establishing it as a pioneer in Italian speleotourism. Scientific exploration intensified in the second half of the 19th century, with paleontological digs revealing a complete Ursus spelaeus skeleton, now reconstructed and displayed in the cave's Hall of the Temple. Post-World War II advancements led to the establishment of an underground karst laboratory in 1969, operated by the Speleological Group of the Maritime Alps (part of the Italian Alpine Club or CAI of Cuneo) in collaboration with the Polytechnic University of Turin's Department of Georesources and Territory. This facility has since become an international center of excellence for research in hydrogeology, underground climatology, speleobiology, and natural radioactivity. In December 2019, the Paléolab was inaugurated by the Polytechnic of Turin in synergy with the karst laboratory, focusing on paleoclimatic studies through analysis of cave sediments and formations. The cave's exploration continued until 1949, with speleological groups still probing its hidden extensions, underscoring its ongoing mystery and scientific value.
Bossea Cave is a classic karst system formed through the dissolution of limestone by carbonic acid-rich water over millions of years. It developed within the Briançonnaise-Ligurian geological series, comprising volcaniclastic sediments such as the Porphyroids of Melogno (Carboniferous to Middle Permian, 275–329 million years ago), Middle Triassic dolomites (about 237 million years ago), and Jurassic Limestones of Bossea (about 172 million years ago). The karst networks likely began forming around 5 million years ago during the uplift of the Alpine massifs and climatic cooling, with intensified development in the Quaternary period due to further uplift and erosion by underground rivers. The cave is the terminal area of a large karst aquifer along the Corsaglia-Maudagna watershed, with a lower zone about 1 kilometer long and a 128-meter descent, fully traversed by a perennial torrent with flow rates ranging from 100 liters per second to over 4,200 liters per second. This torrent drains an estimated 6 million cubic meters of water annually, eroding and dissolving 750–800 tonnes of rock, sculpting immense spaces through landslides and creating vertiginous views with imposing concretions like stalactites, stalagmites, curtains, and icefalls. Structural geology plays a key role: The cave lies at a lithological contact between carbonates and underlying insoluble rocks, with a complex setting involving ESE-WNW strike-slip faults, disharmonic deformation, and a detachment surface between buckled basement meta-volcanics and folded marbles. This tectonic framework facilitates water circulation along folded bedding interfaces and fracture clusters, leading to erosion in the detachment's cataclastic zones and gravitational collapses that form the cave's giant halls.
The cave's layout is divided into two main areas: a lower section with majestic, water-rich environments and an upper area of narrow galleries on multiple levels, separated by features like the waterfall at Lake Ernestina. Visitor tours cover a round-trip distance of about 3 kilometers, showcasing vast panoramas of steep, picturesque landscapes, running waters, and underground lakes. Key features include the Hall of the Temple (Sala del Tempio), which houses the reconstructed Ursus spelaeus skeleton and paleontological exhibits; the Bear Hall (Sala dell'Orso), with Pleistocene-era bear bones and used for events like concerts; and chambers adorned with calcareous concretions in various shapes and colors. The site is biologically rich, hosting 57 species of cave animals, 10 of which are endemic, such as the Plectogona Bosseae millipede and the Palpigrado Eukoenenia Strinati and Troglohyphantes Pedemontanum spiders. Scenic highlights include underground streams, lakes, and imposing spaces sculpted by erosion and collapses, providing a "ten hours of walking to the center of the earth" experience, as one visitor described.
Paleontological discoveries are central to Bossea Cave's allure, with excavations since 1865 yielding bones of Ursus spelaeus from the Pleistocene era (over 10,000 years ago), including a complete skeleton reconstructed in the Hall of the Temple. These finds highlight the cave's role as a prehistoric habitat for cave bears and other fauna. Ongoing research at the Underground Karstology Laboratory (since 1969) and Paléolab (since 2019) focuses on hydrogeology, climatology, speleobiology, radioactivity, and paleoclimatic studies through sediment analysis, making Bossea one of the most examined caves globally. Artifacts like tools or human remains are minimal, but the cave's natural "artifacts"—fossil-rich deposits and concretions—provide invaluable data on Quaternary climates and karst evolution.
As of 2025, Bossea Cave is managed by the Ente di Gestione del Parco
Naturale del Marguareis (Marguareis Natural Park Management Authority)
and remains a protected site with high scientific and touristic value.
It is open year-round except for December 25 and January 1, with guided
tours (90–100 minutes, led by expert speleologists) mandatory for safety
and education. Tour schedules vary: Monday–Friday at 11:00 AM and 3:00
PM; Saturdays at 10:00 AM, 11:00 AM, 3:00 PM, and 4:30 PM; holidays at
10:00 AM, 11:00 AM, 2:30 PM, 4:00 PM, and 5:30 PM (reservations required
via +39 348 735 6250 or info@grottadibossea.com). Entrance fees are €12
for full adult tours (€10 short), €9 for children 3–10 years (€7 short),
with group discounts and free entry for disabled visitors (carers €10).
Visitors should wear suitable clothing and footwear due to the damp, 9°C
environment; the cave is covered for all-weather access. The site
continues as an active research hub, with no reported closures or major
changes in 2025, though visitors should confirm status amid potential
timetable variations from October to February.
In summary, Bossea
Cave stands as a geological marvel and scientific treasure, offering
visitors a profound journey through time via its karst wonders and
prehistoric relics. Its blend of natural beauty, research legacy, and
accessibility makes it an essential destination in Piedmont's alpine
landscape.