Just a few kilometers away from charming villages like Alberobello and Polignano a Mare lie the Castellana Caves, an extensive underground network of karst caves perched at 330 meters above sea level on the southeastern limestone plateau Murge, in Apulia. Recognized as one of Italy’s most stunning cave systems, the Castellana Caves (known as Grotte di Castellana in Italian) span an impressive 3,348 meters in total, reaching a maximum depth of 122 meters below street level.
The allure of the Castellana Caves draws in tourists from around the globe, guiding them along a 3 km-long route through captivating landscapes filled with caverns boasting whimsical names, canyons, deep abysses, fossils, stalactites, stalagmites, and dripstones of extraordinary shapes and vivid colors. These formations spark the imagination of both children and adults alike, creating an unforgettable experience.
In this article, we embark on a virtual journey to uncover the secrets of Castellana Caves, delving into its discovery, geological marvels, and the enchanting experience that awaits those who step into its subterranean realm.
The Genesis of Castellana Caves
The story of the Castellana Caves’ origin takes us back to the upper Cretaceous period, around 90 million years ago, when Apulia rested beneath the waters of the ancient Mediterranean. Inhabited by numerous colonies of mollusks and marine plants, the region witnessed the gradual accumulation of empty shells and carcasses on the seabed over millions of years. This process formed an immense deposit of mud and sand, which, through slow but continuous growth, compressed into a layer of limestone with a thickness spanning several kilometers.
Approximately 65 million years ago, tectonic forces uplifted the region, bringing it to its present-day landscape. The emerged limestone masses displayed extensive cracks due to both the geological process and the inherent rigidity of the limestone itself. The ensuing eluvial deposits, resulting from intense rainfall, trickled into the subsoil, forming an expansive underground aquifer. Over time, this aquifer dissolved the limestone, widening the cracks that progressively connected smaller ducts into larger spaces. This process was further facilitated by collapses of adjacent rocks.
In areas where numerous cracks intersected, significant and repeated collapses occurred. These events expanded the cave toward the ceiling, gradually reducing the thickness of the rock that separated the cavity from the outside world. Eventually, the residual layer thinned out and collapsed, allowing the first rays of light to penetrate the interior of the cave system.
The Dripstone Formation
The enchanting beauty of the Castellana Caves’ aesthetic landscape lies in the rich variety of dripstones that adorn its bare walls. These formations result from the accumulation of calcite deposits over an extended period, carried by rainwater as it slowly permeates through the overlying rocky layers.
Upon reaching the cavernous voids, each water droplet, in its descent to the ground, leaves behind a deposit of calcium carbonate. This process occurs either on the cave’s vault, fostering the growth of stalactites that hang gracefully from the ceiling, or on the floor, contributing to the formation of stalagmites rising from below. As time progresses, the continuous growth of a stalactite and stalagmite culminates in their fusion, giving rise to the formation of majestic columns.
Beyond these common forms, the Castellana Caves boast an array of unique dripstones. Flow-stones and curtains take shape through the flowing motion of water, while coralloids and pond crystals emerge in underwater environments. Adding to the spectacle are helictites, which defy the pull of gravity, and cave pearls, layers of calcite that develop around microscopic grains of rock. Each type of dripstone contributes to the captivating and diverse tapestry that makes exploring the Castellana Caves a truly extraordinary experience.
The Discovery in 1938
The discovery of the Castellana Caves in 1938 is shrouded in tales of mystery and the eerie ambiance of “La Grave”, the local term for the deep sinkhole that serves as the entrance to these subterranean wonders. Situated alongside a country road, the “Grave” has long evoked a sense of trepidation and fear, particularly as nightfall descends. Whispers of bats ascending from the abyss and spectral vapors, believed by the superstitious to be the restless souls of suicide victims, added to the mystique of this ominous locale.
While Vincenzo Longo, a local humanist and jurisconsult, may have been among the first to descend into the “Grave” in the late 18th century, it wasn’t until 1938 that the Provincial Tourist Board of Bari enlisted the expertise of a seasoned speleologist from the Italian Institute of Speleology. The intrepid Franco Anelli, a speleologist of note, stepped into the scene exactly 86 years ago on January 23rd, 1938. Anelli’s journey into the depths of the first cave unveiled a labyrinthine passage leading to a colossal cavern, later named the Cavern of Monuments. The sheer enormity of the second cavern, where even the beam of the acetylene lamp failed to illuminate the walls and ceiling, marked a pivotal moment in the discovery.
Undeterred, Anelli resumed his exploration two days later, accompanied by Vito Matarrese, a brave worker from Castellana. The duo ventured approximately 300 meters before confronting the Serpent Corridor, a short descending tunnel that halted their progress in front of a profound well. In March 1938, Anelli and Matarrese continued their exploration, reaching a distance of 600 meters from the “Grave”. A deep chasm, located in the Corridor of the Desert, compelled them to pause once again. Anelli, demonstrating both courage and meticulousness, began mapping the caves during his third visit in September of the same year.
Following Anelli’s departure, Vito Matarrese, in solo pursuits, overcame the chasm of the Corridor of the Desert and reached the culmination of the karst system – the White Cave, discovered in 1939. Yet, the secrets of the “Grave” remain elusive. A depression uncovered at the base of the north wall hints at undiscovered corners and unexplored cavities. Excursions and geophysical research on-site, employing various survey techniques, have raised the possibility of additional branches stemming from the initial chasm, suggesting that the exploration of the “Grave” is an ongoing journey, with new discoveries awaiting those who dare to delve into its depths.
Long and Short Tours
Exploring the Castellana Caves is an immersive experience guided by a team of multilingual and seasoned staff, ensuring visitors embark on a journey filled with awe and wonder. The guided tour follows a comfortably paved trail, guiding visitors roughly 70 meters underground into a mesmerizing landscape adorned with stalactites, stalagmites, fossils, cavities, and intricate caves.
To accommodate diverse preferences, two distinct itineraries are available for those eager to visit the Castellana Caves. The long itinerary spans approximately 3 kilometers and takes around 100 minutes to complete, offering a comprehensive exploration of the underground wonders. Alternatively, the short itinerary covers approximately 1 kilometer and lasts approximately 50 minutes, providing a condensed yet captivating experience.
The Castellana Caves remain open throughout the year. To plan your visit, you are encouraged to consult the official website for the varied schedules of excursions. The cave maintains a consistent temperature ranging between 14° and 18° Celsius. As such, it is recommended to dress in accordance with the underground climate, opting for comfortable attire, and wear sneakers with a flat rubber sole for ease of navigation.
Inside the caves, visitors are treated to encounters with the cave’s most characteristic inhabitants, notably bats. With a presence marked by five different species, these winged creatures add an element of intrigue to the subterranean landscape. Additionally, the Castellana Caves have been a haven for newfound endemic species, discovered through bio-speleological research. Among these fascinating inhabitants are the isopod crustaceans Murgeoniscus Anellii and Castellanethes Sanfilippoi, the pseudoscorpion Hadoblothrus gigas, the pselafid beetle Tychobythinus Anellii, and the carabid beetle Italodytes stammeri. For the fortunate visitor, a sighting of the orthoptera Troglophilus Andreinii, a species of cave-dwelling grasshopper, might add an extra layer of excitement to the exploration.
Castellana Caves by Night
For those seeking a truly unique and immersive experience within the Castellana Caves, the Speleo Night Tour offers an extraordinary adventure. This exclusive visit unfolds in the dark, showcasing a different facet of the karst site. Conducted after public hours, the Speleo Night Tour caters to groups of at least 15 people, providing an intimate exploration of the caves under the guidance of two expert spelunkers.
Participants embark on the entire itinerary, including an additional leg not covered in the standard tourist route, equipped with helmets featuring front lights that at some points are turned off. The journey begins at the “Grave”, where the significance of this nocturnal exploration is conveyed, instilling a sense of true adventure among the participants. Proceeding through the Cave of the She-Wolf, visitors witness the enchanting sight of transparent water droplets, illuminated with LED lights, shimmering like silver on the vault.
In the Monument Cavern, an extraordinary moment occurs as all lights are extinguished, and one of the guides demonstrates the cave’s appearance using only a mining light burning acetylene. This attempt to recreate the conditions faced by the first explorers adds a historical dimension to the experience. The adventure then leads into the Cave of Corals, a small yet remarkably beautiful side branch.
Returning to the main itinerary in the Cave of the Owl, participants receive insights into the caves’ flora and fauna, with a focus on nocturnal animal life forms. The group is temporarily divided, navigating two parallel corridors in the Cave of the Abyss to simulate a genuine exploration feeling.
The Desert Corridor marks a thrilling moment as visitors walk 500 meters in solitude, fostering a profound connection with the cave and an intimate bond with Mother Earth. Reassembling the group, the journey continues to the Cave of the Leaning Tower, where the colors and shapes of the speleothems undergo a captivating transformation.
In the Dome Cave, an encore of darkness unfolds, with all lights, including those of the guides, extinguished. This deliberate plunge into absolute darkness heightens the sense of hearing and amplifies the perception of water droplets resonating from the ceiling to the ground. Emerging into the White Cave, participants transition from darkness to the brilliance of pure white, intensified by the artificial lights within the caves.
The return journey to the “Grave” is illuminated by the artificial light system, allowing participants to appreciate the macroscopic aspects of the caves after immersing themselves in the magic of the microscopic realm during the darkened tour. The Speleo Night Tour promises an unparalleled and enchanting adventure for those eager to explore the Castellana Caves in a truly extraordinary way.
