Castellana Caves, Show cave in Castellana Grotte, Italy.

Castellana Caves are a karst cave system in the municipality of Castellana Grotte, Apulia, opening in the south-eastern Murge limestone plateau at 330 metres above sea level. The system is 3,348 metres long and reaches a maximum depth of 122 metres. The temperature inside is about 18 °C. The entrance is the 60-metre-deep shaft La Grave, 100 metres long and 50 metres wide, whose collapsed roof lets a sunbeam fall on a group of stalagmites called the Cyclopes.

The speleologist Franco Anelli first entered the system in January 1938, discovering the deep shaft known as La Grave and further chambers. His work led to systematic exploration and the later opening of the caves to visitors in the following years.

The system takes its name from the nearby town of Castellana, while the grottos have served as a popular destination in Apulia since opening to visitors. Inside, halls such as the White Cave and the Cavern of Monuments carry Italian names referring to their appearance and discovery.

Visitors can choose between two guided routes: a shorter walk of about one kilometer or a longer path extending around three kilometers. Sturdy footwear is recommended, as the paths pass through natural formations and can be uneven in places.

In the so-called White Cave, bright alabaster and calcite crystals reflect light, creating soft shading on the walls. This section is considered one of the brightest natural spaces in the entire system.