Near the town of Castellana Grotte in Puglia, southern Italy, a narrow entrance opens into a much larger underground landscape. The Castellana Caves are a karst system in limestone, formed as water moved through fractures in the rock and gradually enlarged passages and chambers. The official cave site places the complex in the south-eastern Murge and describes an underground route extending for more than three kilometres.
The limestone plateau developed from marine sediments during the Upper Cretaceous, around 90 million years ago, according to the site’s geological account. That timescale is difficult to grasp during a visit, but the cave walls make the process visible in layers, hollows and mineral deposits. Stalactites, stalagmites, columns and curtains are not sculpted decorations; they are formations created slowly by water and mineral precipitation.
