The Castellana Caves (Grotte di Castellana) are a network of underground caves located in the town of Castellana Grotte in the Apulia region of southern Italy. The caves were first discovered in 1938 and have since become a popular tourist attraction, drawing visitors from all over the world.

The Castellana Caves are a series of limestone formations that were formed over millions of years by the action of water on the rock. The caves extend for over 3 kilometers (1.9 miles) and are divided into three sections: the White Cave, the Black Cave, and the Red Cave.

The White Cave is the first and most famous section of the caves, featuring stunning white limestone formations that have been carved out by centuries of flowing water. The Black Cave is named for its dark walls and features several large caverns, while the Red Cave is known for its red limestone formations and intricate stalactites and stalagmites.

Guided tours of the Castellana Caves are available year-round and take visitors through all three sections of the cave network. Along the way, visitors can see a variety of unique limestone formations, underground lakes and streams, and even prehistoric fossils.