The Caves of Castellana open in south-eastern Murge, a limestone plateau dating back to the upper Cretaceous (ninety- one 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 Limestone of Altamura. The cave system is 3348 metres 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