Castellana Caves

About

The Castellana Caves (Italian: Grotte di Castellana) are a karst cave system located in the municipality of Castellana Grotte, in the Metropolitan City of Bari, Apulia, southern Italy.

The caves, discovered in 1938 by the speleologist Franco Anelli, are situated 1 kilometer (0.62 mi) south of Castellana and are served by the ( Grotte di Castellana railway station ) on the FSE line Bari - Putignano - Martina - Taranto.

The entrance is represented by an enormous vertical tunnel 60 meters (200 ft) long. The main cave is named " La Grave " (as abyss), and others are named Black Cavern ( Caverna Nera ), White Cave ( Grotta Bianca ) and Precipice Cavern ( Caverna del Precipizio ).

The Caves of Castellana open in south-eastern Murge, a limestone plateau dating to the upper Cretaceous (ninety-hundred million years ago) and rising 330 metres above sea level. The area of Castellana is characterized by limestone, a sedimentary rock composed largely of calcium carbonate, known as the Limestone of Altamura. The cave system is 3348 meters in length and the point of maximum depth reaches 122 metres. The temperature within the caves is about 18 °C.

The caves are open all year round except for Christmas Day and New Year's Day. The visit develops along two itineraries: the first is 1 km long and lasts about 50 minutes while the second is 3 km long and lasts about two hours. During the summer there are also guided night tours. The Grave is the first and the biggest cave. It measures 100 m in length, 50 m in width, and 60 m in depth. Going beyond the Grave stalactites, stalagmites, curtains, and crystals continue to embellish the caves. The names of the environment are the result of the imagination of the early explorers: the She-Wolf, the Monuments, the Owl, the Little Virgin Mary, the Altar, the Precipice, the Desert Corridor, the Reverse Column, the Red Corridor, the Dome up to the last and the most dazzling one, the White Cave.

Castellana's speleological complex is unique among other cave systems due to its three peculiarities: the Grave, the White Cave and the concretions.

The Grave of Castellana is large due to its natural skylight surrounded by a circle of holm-oaks through which a ribbon of clear sky is visible. From the ceiling, a big sunbeam filters into the cave. Within the Grave, the sunlight illuminates a stalagmite group, called the Cyclopes because they look like sea giants rising out of a stormy sea. The southern walls, the big broken curtain,n s, and the green moss-grown columns stay always in the darkness. Beyond these columns, are the architectural structures. The Grave is the first cave of the karst system and the only one communicating with the outside. Its history dates to ninety-one hundred million years ago in the upper Cretaceous. At that time Apulia was submerged by a sea where lived large colonies of molluscs and sea vegetables. For millions of years, generations of these life forms-plants and marine mollusks succeeded each other and died, so their empty shells and their carcasses were piled on the seabed, forming a giant deposit of mud and sand, that with continuous growth was compressed forming limestone layers for a thickness of several kilometers. Starting 66 million years ago, the gradual raising of the land brought the region to its current aspect. However, the newly emerged land was too rigid and for this reason, it was fractured. The eluvial water of large rainfall infiltrated the subsurface soil and rock creating a groundwater aquifer. The physical and chemical effects of water running underground dissolved the limestone and enlarged the fractures. Over geological eras, cracks expanded to become galleries and then caverns. In some instances, numerous cracks intersected, leading to frequent collapses. The thickness of the rock separating the cave from the outside had diminished significantly, causing the vault to collapse. This occurred in the Grave of Castellana, allowing sunlight into the cave.

At the end of the underground itinerary and about 1500 metres from the Grave there is a small portal dig in an alabaster wall. This is the entrance of the White Cave. The white alabaster and drip water crystals cover every corner with very white translucent stalagmites. This includes two high and large columns that seem to support the vault with white stalactites and coral concretions.

A feature of the Caves of Castellana are the concretions, the mineral deposits that covered the walls of a cave by crystallisation of the calcite carried in solution by infiltrating rain water, that had penetrated the overhanging layers of the rock. When the water drips through the roof of an empty cavern, the calcite dissolved in it deposits on the roof and going downwards takes the shape of a stalactite. When the drop of water falls on the floor, the calcite takes the shape of a stalagmite. As time went by, the downwards extension of a stalactite and the progressive growth of the below stalagmite led to the formation of a column. Besides these elementary forms, there are other concretions such as calcite flowstones, curtains, (which are due to the flowing of water), corals, calcite crystals, (which formed underwater), cave pearls, formed of concentric layers as calcite crystallizes on a nucleus such as a microscopic grain of rock, and the eccentric concretions. Some stalactites grow multi-directionally, i.e. horizontally to the floor, developing curved patterns.

According to speleology, there are several hypotheses about their origin of the unusual stalactites. The first factor is the possible presence of draughts in the caves that would drive horizontally the direction of the drops and therefore the growth of the concretion. The second factor has to do with the particular form in which calcite crystallizes. Calcite is a mineral that crystallizes in the trigonal system and has perfect rhombohedral cleavage. The cannula of a stalactite is formed by a series of very small rhombohedra which interpenetrate each other. If, as consequence of several causes, the cannula is perforated on the side, water will come out through that opening and will create an aggregate of other rhombohedra on the side. The third one is the presence of any impurities in the water. They can hinder the growth of a calcite rhombohedron in a direction and thus it can form an aggregate on the side that will follow a different direction.

There are also eccentric stalactites whose central cannula is very thin (the diameter is less than one millimetre) and so the water flows very slowly. At the end of this stalactite there is always a droplet whose calcite crystals can align randomly so the formation follows a new direction.

The Caves of Castellana open in south-eastern Murge, a limestone plateau dating to the upper Cretaceous (ninety-hundred million years ago) and rising 330 metres above sea level. The area of Castellana is characterized by limestone, a sedimentary rock composed largely of calcium carbonate, known as the Limestone of Altamura. The cave system is 3348 meters in length and the point of maximum depth reaches 122 metres. The temperature within the caves is about 18 °C.

The caves are open all year round except for Christmas Day and New Year's Day. The visit develops along two itineraries: the first is 1 km long and lasts about 50 minutes while the second is 3 km long and lasts about two hours. During the summer there are also guided night tours. The Grave is the first and the biggest cave. It measures 100 m in length, 50 m in width, and 60 m in depth. Going beyond the Grave stalactites, stalagmites, curtains, and crystals continue to embellish the caves. The names of the environment are the result of the imagination of the early explorers: the She-Wolf, the Monuments, the Owl, the Little Virgin Mary, the Altar, the Precipice, the Desert Corridor, the Reverse Column, the Red Corridor, the Dome up to the last and the most dazzling one, the White Cave.

Castellana's speleological complex is unique among other cave systems due to its three peculiarities: the Grave, the White Cave and the concretions.

of Castellana is large due to its natural skylight surrounded by a circle of holm-oaks through which a ribbon of clear sky is visible. From the ceiling, a big sunbeam filters into the cave. Within the Grave, the sunlight illuminates a stalagmite group, called the Cyclopes because they look like sea giants rising out of a stormy sea. The southern walls, the big broken curtain,n s, and the green moss-grown columns stay always in the darkness. Beyond these columns, are the architectural structures. The Grave is the first cave of the karst system and the only one communicating with the outside. Its history dates to ninety-one hundred million years ago in the upper Cretaceous. At that time Apulia was submerged by a sea where lived large colonies of molluscs and sea vegetables. For millions of years, generations of these life forms-plants and marine mollusks succeeded each other and died, so their empty shells and their carcasses were piled on the seabed, forming a giant deposit of mud and sand, that with continuous growth was compressed forming limestone layers for a thickness of several kilometers. Starting 66 million years ago, the gradual raising of the land brought the region to its current aspect. However, the newly emerged land was too rigid and for this reason, it was fractured. The eluvial water of large rainfall infiltrated the subsurface soil and rock creating a groundwater aquifer. The physical and chemical effects of water running underground dissolved the limestone and enlarged the fractures. Over geological eras, cracks expanded to become galleries and then caverns. In some instances, numerous cracks intersected, leading to frequent collapses. The thickness of the rock separating the cave from the outside had diminished significantly, causing the vault to collapse. This occurred in the Grave of Castellana, allowing sunlight into the cave.

At the end of the underground itinerary and about 1500 metres from the Grave there is a small portal dig in an alabaster wall. This is the entrance of the White Cave. The white alabaster and drip water crystals cover every corner with very white translucent stalagmites. This includes two high and large columns that seem to support the vault with white stalactites and coral concretions.

A feature of the Caves of Castellana are the concretions, the mineral deposits that covered the walls of a cave by crystallisation of the calcite carried in solution by infiltrating rain water, that had penetrated the overhanging layers of the rock. When the water drips through the roof of an empty cavern, the calcite dissolved in it deposits on the roof and going downwards takes the shape of a stalactite. When the drop of water falls on the floor, the calcite takes the shape of a stalagmite. As time went by, the downwards extension of a stalactite and the progressive growth of the below stalagmite led to the formation of a column. Besides these elementary forms, there are other concretions such as calcite flowstones, curtains, (which are due to the flowing of water), corals, calcite crystals, (which formed underwater), cave pearls, formed of concentric layers as calcite crystallizes on a nucleus such as a microscopic grain of rock, and the eccentric concretions. Some stalactites grow multi-directionally, i.e. horizontally to the floor, developing curved patterns.

According to speleology, there are several hypotheses about their origin of the unusual stalactites. The first factor is the possible presence of draughts in the caves that would drive horizontally the direction of the drops and therefore the growth of the concretion. The second factor has to do with the particular form in which calcite crystallizes. Calcite is a mineral that crystallizes in the trigonal system and has perfect rhombohedral cleavage. The cannula of a stalactite is formed by a series of very small rhombohedra which interpenetrate each other. If, as consequence of several causes, the cannula is perforated on the side, water will come out through that opening and will create an aggregate of other rhombohedra on the side. The third one is the presence of any impurities in the water. They can hinder the growth of a calcite rhombohedron in a direction and thus it can form an aggregate on the side that will follow a different direction.

There are also eccentric stalactites whose central cannula is very thin (the diameter is less than one millimetre) and so the water flows very slowly. At the end of this stalactite there is always a droplet whose calcite crystals can align randomly so the formation follows a new direction.

In 1938 the Provincial Tourist Board of Bari asked the Italian Institute of Speleology of Postojna for a speleologist to make an inspection in some caves of the area that have been already explored to turn them into a tourist attraction. But none of them, because of their limited extension, was in this way useful.