Grotte di Castellana: Puglia’s Underground Wonder

On 23 January 1938, the speleologist Franco Anelli descended on a rope into a natural shaft called La Grave — 60 metres deep, pitch dark, with no knowledge of what was below. What he found was a cave system stretching 3 kilometres through the limestone bedrock of Puglia, formed over 90 million years by water dissolving its way through rock. The caves had been there the whole time. Nobody knew.

Grotte di Castellana is Italy’s longest and most spectacular cave system — a sequence of chambers and tunnels beneath the town of Castellana Grotte in the province of Bari, culminating in the Grotta Bianca: a chamber of pure white alabaster-like formations considered the most beautiful cave room in the country. The temperature inside never rises above 18°C. The scale of the chambers — some reaching cathedral height — is impossible to convey in photographs. It requires being inside.

What Are the Grotte di Castellana?

The Grotte di Castellana is one of Italy’s longest and most spectacular cave systems, located just outside the town of Castellana Grotte in the province of Bari. This underground wonder stretches for more than 3 kilometers through a complex network of tunnels.

The caves are a classic example of karst geology — formed when slightly acidic rainwater slowly dissolved the limestone bedrock over millennia. What remains is a natural labyrinth of stalactites, stalagmites, and dazzling mineral deposits in ever-changing shapes and colors. The atmosphere inside is surreal, cool, and silent, with chambers of cathedral-like scale.

Visitors follow a guided path beginning at La Grave, a 60-meter-deep vertical shaft open to the sky. From there, the route leads through caves with poetic names like the Cavern of the Monuments, Desert Corridor, and Cavern of the Precipice, each with unique geological features. The crown jewel is the White Cave (Grotta Bianca) — a chamber filled with pure white alabaster-like formations that seem to glow from within.

Exploring the Grotte di Castellana means entering a hidden world beneath the Puglian soil — a place where time, water, and stone have shaped a breathtaking natural cathedral.

Discovery: A Leap into the Unknown

The Grotte di Castellana were discovered on January 23, 1938, by Italian speleologist Franco Anelli, a researcher with the Italian Institute of Speleology. Anelli, with only ropes and lanterns, descended into a natural shaft known as La Grave, venturing where no one had dared to go. Local boy Vito Matarrese assisted in the first explorations, becoming the second human to witness the underground chambers. Their discovery led to the opening of the caves to the public later that same year, turning Castellana into one of Puglia’s top tourist destinations.

The descent into La Grave was not comfortable. The shaft drops nearly 60 metres through total darkness — a vertical drop requiring the confidence to commit to a rope with no knowledge of the bottom. Anelli later described the silence at the base as the most profound he had ever experienced: no wind, no water sound, no echo. Just stillness, and the awareness that no human being had ever stood in this place before.

Local teenager Vito Matarrese had actually been the first to be lowered part-way into La Grave some years earlier — not for scientific purposes, but as a childhood dare. He was pulled back up before reaching the bottom, frightened by the depth and the dark. When Anelli’s team arrived, Matarrese served as guide, knowing the shaft’s character from his own encounter with it. The caves opened to the public later in 1938, the same year they were discovered. They have been visited by millions of people since.

Visiting the Grotte di Castellana: What You Need to Know

🎟️ Recommended Booking Platforms:

• Viator Tour
• Official Website

📅 Best Time to Visit

The caves maintain a constant temperature of 16–18°C year-round — cool in summer, relatively warm in winter. This means the Grotte di Castellana work in any season, but the visitor experience varies significantly.

Spring (April–May) and Autumn (September–October) are the best windows — comfortable outdoor temperatures, shorter queuing times, and the surrounding Itria Valley landscape at its most attractive.

Summer (July–August) is the busiest period. Italian school groups visit heavily in June and early July; the caves fill with tour groups and queuing times increase. If you’re visiting in peak summer, book in advance online and choose the first morning tour at 10am — it’s consistently the least crowded slot of the day.

Winter (November–March) is genuinely excellent for the Grotte. Almost no queuing, the coolness of the caves is comfortable relative to the mild outdoor temperatures, and the nearby towns of Alberobello and Polignano are at their most atmospheric. The caves don’t know what season it is outside.

💡 Book online. The official website (grottedicastellana.it) and Viator both allow advance booking. In July and August this is not optional — tours sell out. In other seasons it’s still worth doing to guarantee your preferred time slot.

Accessibility & Tips

• Parking: Large paid parking area nearby.
• Accessibility: The caves are accessible to visitors with limited mobility.
• Kids: Perfect for children 6+, although strollers are not allowed.
• What to wear: Comfortable shoes with grip; a light jacket for cooler cave temperature.
• Photos: Photography is allowed without flash.

The White Cave: The Grand Finale

The Grotta Bianca (White Cave) is reached only on the full 3-kilometre tour, approximately 100 minutes into the visit — and the placement is deliberate. The route builds through progressively more dramatic chambers before delivering this final space, whose effect depends partly on contrast.

The cave takes its name from the colour of its formations. The stalactites, stalagmites, and calcite crystals coating every surface are an almost pure white — the result of the specific mineral composition of the water that deposited them over millennia. The whiteness is not uniform: there are shadings of cream, ivory, and the faintest grey in the shadows, and the formations vary from delicate needle crystals to bulbous masses the size of tree trunks. In the lamplight used during tours, the surfaces appear to glow rather than merely reflect.

Photographs of the Grotta Bianca exist in abundance. None of them prepare you for the actual scale of the chamber, the quality of the silence inside it, or the specific texture of the white formations at close range. This is one of those natural spaces — like the interior of the Pantheon, like Fingal’s Cave — where photographs function as a reminder rather than a substitute for presence.

The Grotta Bianca alone justifies choosing the full route over the short one. If you are physically capable of the 3-kilometre walk, take the full tour.

How to Get There

• By Car: 40 km from Bari, 15 km from Alberobello. Use SS100 or SP237.
• By Train: Ferrovie Sud Est trains connect Bari with Castellana Grotte station (15 min walk from the caves).
• By Tour: Day trips available from Bari, Polignano, and Monopoli.

Nearby Places to Visit

Make the most of your day in the area. Here are five nearby attractions worth adding to your itinerary:

Final Tips for Travelers to Grotte di Castellana

• Book your tour in advance, especially during weekends and holidays.
• Combine your visit with a walk through the nearby town of Castellana Grotte — less touristy, full of local charm.
• Don’t skip the full route if you’re fit and curious — the White Cave is worth every step.
• If you’re traveling with kids or seniors, the short route still offers an incredible experience.

❓ Frequently Asked Questions