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
Bossea Cave, known in Italian as Grotta di Bossea, is a prominent karst
cave system located in the upper Val Corsaglia valley near Frabosa
Soprana in the Province of Cuneo, Piedmont region of northwestern Italy.
Situated at an elevation of 836 meters above sea level within the
Natural Park of the Marguareis Massif, it is renowned for its vast
dimensions, scenic underground river, rich speleothems (such as
stalactites, stalagmites, flowstones, and rimstone pools), and
significant paleontological and biological value. The cave spans over 3
kilometers in explorable length with a vertical range of about 116
meters and a total volume exceeding 900,000 cubic meters. It features an
active subterranean river that carries an average annual flow of over
five million cubic meters of water, eroding approximately 750-800 tons
of rock from the karst system each year. This river, named after local
explorer Domenico Mora, exhibits flow rates varying from 50 to 2,500
liters per second, contributing to the cave's dynamic and erosive
environment. The cave's history intertwines early human exploration,
groundbreaking scientific discoveries, and pioneering development as one
of Italy's first show caves, making it a key site for both tourism and
research.
Early Discovery and Initial Explorations (19th Century)
The
earliest documented evidence of human entry into Bossea Cave dates back
to the early 19th century. An inscription reading "Mateo 27 LUGLIO 1816"
was discovered in the summer of 2015 in the area of the Temple Hall,
confirming visits as far back as 1816 and suggesting the cave was known
locally around 200 years ago (relative to modern records from the
2010s). However, systematic exploration began later in the century.
In 1850, a group of locals led by Domenico Mora conducted the first
recorded exploration, penetrating deep into the cave and reaching what
is now known as Lake Ernestina. This marked the beginning of more
organized ventures into the cave's interior, which revealed its
impressive scale, including large chambers like Sala Garelli (measuring
150 meters long, 60 meters wide, and 50-80 meters high) adorned with
flowstones, curtains, and waterfalls. The lower zone of the cave is
characterized by its imposing size and active river, while the upper
zones consist of complex tunnels on multiple superimposed levels,
separated by features like the Ernestina Lake waterfall.
A pivotal
moment came in June 1865 when remains of the extinct cave bear (Ursus
spelaeus) were discovered during further explorations. This was the
first such find in Italy, catapulting the cave to national and
international fame. Analysis of the bones indicated they belonged
primarily to very old or very young bears, suggesting the cave served as
a hibernation and birthing site between approximately 80,000 and 12,000
years ago. Bears likely entered through now-collapsed entrances during
the Pleistocene epoch, with many perishing during hibernation due to age
or infancy. A reconstructed skeleton from these finds is now displayed
in the Temple Hall, serving as a highlight for visitors.
By 1874, an
expedition successfully navigated beyond a major waterfall, accessing
the canyon section and expanding the known extent of the cave. These
efforts laid the groundwork for the cave's transformation into a public
attraction.
Development as a Show Cave and Tourism Boom (Late
19th to Early 20th Century)
On August 2, 1874, Bossea Cave was
officially opened to the public by Senator Giovanni Garelli from
Mondovì, becoming the first dedicated tourist cave in Italy (though some
sources note Grotte Oliero may have opened slightly earlier, Bossea is
widely recognized as the pioneer). This opening capitalized on the
cave's growing fame following the 1865 cave bear discovery, attracting a
large influx of visitors in the late 19th century. Early tours were
rudimentary, but the cave's natural wonders—such as its underground
river, panoramic chambers, and calcareous concretions in various shapes
and colors—drew crowds. Historic engravings by Giuseppe Barberis,
published in Gustavo Strafforello's 1891 book on the Province of Cuneo,
captured the cave's allure and helped promote it further.
The cave
enjoyed significant popularity through the early 20th century, but
tourism likely declined during World War II, leading to a temporary
closure. It was reopened in 1948 with renovated trails and the
installation of electric lighting, enhancing safety and visitor
experience. By 1949, explorations of the main branches were completed,
solidifying the cave's mapped extent.
Scientific Research and
Modern Developments (Mid-20th Century to Present)
Bossea Cave's
scientific importance has grown alongside its tourism. In 1964, a
scientific station was established inside the cave to study biological
phenomena, marking the beginning of ongoing research. This was expanded
in 1969 with the installation of a dedicated scientific station by the
Speleological Group of the Maritime Alps (part of the Italian Alpine
Club, or CAI, of Cuneo). The laboratory, located in the chamber La
Sacrestia near Salone dell’Orso, has been operated by researchers like
Enrico Lana (for over a decade) and is now managed collaboratively by
the Central Italian Alpine Club, the Polytechnic of Turin, and ARPA
Piedmont. Studies focus on cave biology, hydrology, and geology.
Biologically, the cave hosts at least 57 species of cave animals,
including 10 endemic troglobites (organisms adapted to cave life). A
notable example is the pseudoscorpion Pseudoblothus ellingseni (Beier,
1929), which is unique to this cave. Hydrological research, including
water tracing experiments, has revealed that the underground river's
full course spans 15-20 kilometers, with only about 4,000 meters
currently explored. A deep siphon (50 meters deep and 150 meters long)
at the end of the tourist section suggests potential for further
discoveries.
In 2011, the Riserva naturale delle Grotte di Bossea
(Bossea Caves Natural Reserve) was established to protect the site and
its surrounding area. Today, the cave is managed by Società Sciovie
Fontane s.r.l. and offers guided tours: a full "Giro Completo" (3 km,
100 minutes) and a shorter "Giro Breve" (850 m, 60 minutes). Visits
require reservations, with accommodations for groups in English or
German at an extra cost. The constant internal temperature of 9°C
necessitates appropriate clothing, and the site remains open year-round
except for December 25 and January 1. Modern surveys, including
terrestrial laser scanning, continue to document the cave's unique
features, such as wavy carbonate flowstone deposits, underscoring its
ongoing geological interest.
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.